Server CVEs.
Published CVEs that affect server software, ranked by exploit odds.
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CVE-2021-45105
Apache Log4j2 versions 2.0-alpha1 through 2.16.0 (excluding 2.12.3 and 2.3.1) did not protect from uncontrolled recursion from self-referential lookups. This allows an attacker with control over Thread Context Map data to cause a denial of service when a crafted string is interpreted. This issue was fixed in Log4j 2.17.0, 2.12.3, and 2.3.1.
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CVE-2024-31309
HTTP/2 CONTINUATION DoS attack can cause Apache Traffic Server to consume more resources on the server. Version from 8.0.0 through 8.1.9, from 9.0.0 through 9.2.3 are affected. Users can set a new setting (proxy.config.http2.max_continuation_frames_per_minute) to limit the number of CONTINUATION frames per minute. ATS does have a fixed amount of memory a request can use and ATS adheres to these limits in previous releases. Users are recommended to upgrade to versions 8.1.10 or 9.2.4 which fixes the issue.
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CVE-2020-9490
Apache HTTP Server versions 2.4.20 to 2.4.43. A specially crafted value for the 'Cache-Digest' header in a HTTP/2 request would result in a crash when the server actually tries to HTTP/2 PUSH a resource afterwards. Configuring the HTTP/2 feature via "H2Push off" will mitigate this vulnerability for unpatched servers.
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CVE-2024-27316
HTTP/2 incoming headers exceeding the limit are temporarily buffered in nghttp2 in order to generate an informative HTTP 413 response. If a client does not stop sending headers, this leads to memory exhaustion.
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CVE-2024-25617
Squid is an open source caching proxy for the Web supporting HTTP, HTTPS, FTP, and more. Due to a Collapse of Data into Unsafe Value bug ,Squid may be vulnerable to a Denial of Service attack against HTTP header parsing. This problem allows a remote client or a remote server to perform Denial of Service when sending oversized headers in HTTP messages. In versions of Squid prior to 6.5 this can be achieved if the request_header_max_size or reply_header_max_size settings are unchanged from the default. In Squid version 6.5 and later, the default setting of these parameters is safe. Squid will emit a critical warning in cache.log if the administrator is setting these parameters to unsafe values. Squid will not at this time prevent these settings from being changed to unsafe values. Users are advised to upgrade to version 6.5. There are no known workarounds for this vulnerability. This issue is also tracked as SQUID-2024:2
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CVE-2024-27983
An attacker can make the Node.js HTTP/2 server completely unavailable by sending a small amount of HTTP/2 frames packets with a few HTTP/2 frames inside. It is possible to leave some data in nghttp2 memory after reset when headers with HTTP/2 CONTINUATION frame are sent to the server and then a TCP connection is abruptly closed by the client triggering the Http2Session destructor while header frames are still being processed (and stored in memory) causing a race condition.
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CVE-2021-33620
Squid before 4.15 and 5.x before 5.0.6 allows remote servers to cause a denial of service (affecting availability to all clients) via an HTTP response. The issue trigger is a header that can be expected to exist in HTTP traffic without any malicious intent by the server.
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CVE-2021-22883
Node.js before 10.24.0, 12.21.0, 14.16.0, and 15.10.0 is vulnerable to a denial of service attack when too many connection attempts with an 'unknownProtocol' are established. This leads to a leak of file descriptors. If a file descriptor limit is configured on the system, then the server is unable to accept new connections and prevent the process also from opening, e.g. a file. If no file descriptor limit is configured, then this lead to an excessive memory usage and cause the system to run out of memory.
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CVE-2019-11248
The debugging endpoint /debug/pprof is exposed over the unauthenticated Kubelet healthz port. The go pprof endpoint is exposed over the Kubelet's healthz port. This debugging endpoint can potentially leak sensitive information such as internal Kubelet memory addresses and configuration, or for limited denial of service. Versions prior to 1.15.0, 1.14.4, 1.13.8, and 1.12.10 are affected. The issue is of medium severity, but not exposed by the default configuration.
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CVE-2022-0778
The BN_mod_sqrt() function, which computes a modular square root, contains a bug that can cause it to loop forever for non-prime moduli. Internally this function is used when parsing certificates that contain elliptic curve public keys in compressed form or explicit elliptic curve parameters with a base point encoded in compressed form. It is possible to trigger the infinite loop by crafting a certificate that has invalid explicit curve parameters. Since certificate parsing happens prior to verification of the certificate signature, any process that parses an externally supplied certificate may thus be subject to a denial of service attack. The infinite loop can also be reached when parsing crafted private keys as they can contain explicit elliptic curve parameters. Thus vulnerable situations include: - TLS clients consuming server certificates - TLS servers consuming client certificates - Hosting providers taking certificates or private keys from customers - Certificate authorities parsing certification requests from subscribers - Anything else which parses ASN.1 elliptic curve parameters Also any other applications that use the BN_mod_sqrt() where the attacker can control the parameter values are vulnerable to this DoS issue. In the OpenSSL 1.0.2 version the public key is not parsed during initial parsing of the certificate which makes it slightly harder to trigger the infinite loop. However any operation which requires the public key from the certificate will trigger the infinite loop. In particular the attacker can use a self-signed certificate to trigger the loop during verification of the certificate signature. This issue affects OpenSSL versions 1.0.2, 1.1.1 and 3.0. It was addressed in the releases of 1.1.1n and 3.0.2 on the 15th March 2022. Fixed in OpenSSL 3.0.2 (Affected 3.0.0,3.0.1). Fixed in OpenSSL 1.1.1n (Affected 1.1.1-1.1.1m). Fixed in OpenSSL 1.0.2zd (Affected 1.0.2-1.0.2zc).
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CVE-2021-28662
An issue was discovered in Squid 4.x before 4.15 and 5.x before 5.0.6. If a remote server sends a certain response header over HTTP or HTTPS, there is a denial of service. This header can plausibly occur in benign network traffic.
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CVE-2023-43622
An attacker, opening a HTTP/2 connection with an initial window size of 0, was able to block handling of that connection indefinitely in Apache HTTP Server. This could be used to exhaust worker resources in the server, similar to the well known "slow loris" attack pattern. This has been fixed in version 2.4.58, so that such connection are terminated properly after the configured connection timeout. This issue affects Apache HTTP Server: from 2.4.55 through 2.4.57. Users are recommended to upgrade to version 2.4.58, which fixes the issue.
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CVE-2024-6119
Issue summary: Applications performing certificate name checks (e.g., TLS clients checking server certificates) may attempt to read an invalid memory address resulting in abnormal termination of the application process. Impact summary: Abnormal termination of an application can a cause a denial of service. Applications performing certificate name checks (e.g., TLS clients checking server certificates) may attempt to read an invalid memory address when comparing the expected name with an `otherName` subject alternative name of an X.509 certificate. This may result in an exception that terminates the application program. Note that basic certificate chain validation (signatures, dates, ...) is not affected, the denial of service can occur only when the application also specifies an expected DNS name, Email address or IP address. TLS servers rarely solicit client certificates, and even when they do, they generally don't perform a name check against a reference identifier (expected identity), but rather extract the presented identity after checking the certificate chain. So TLS servers are generally not affected and the severity of the issue is Moderate. The FIPS modules in 3.3, 3.2, 3.1 and 3.0 are not affected by this issue.
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CVE-2021-27212
In OpenLDAP through 2.4.57 and 2.5.x through 2.5.1alpha, an assertion failure in slapd can occur in the issuerAndThisUpdateCheck function via a crafted packet, resulting in a denial of service (daemon exit) via a short timestamp. This is related to schema_init.c and checkTime.
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CVE-2022-36021
Redis is an in-memory database that persists on disk. Authenticated users can use string matching commands (like `SCAN` or `KEYS`) with a specially crafted pattern to trigger a denial-of-service attack on Redis, causing it to hang and consume 100% CPU time. The problem is fixed in Redis versions 6.0.18, 6.2.11, 7.0.9.
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CVE-2019-9511
Some HTTP/2 implementations are vulnerable to window size manipulation and stream prioritization manipulation, potentially leading to a denial of service. The attacker requests a large amount of data from a specified resource over multiple streams. They manipulate window size and stream priority to force the server to queue the data in 1-byte chunks. Depending on how efficiently this data is queued, this can consume excess CPU, memory, or both.
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CVE-2023-38039
When curl retrieves an HTTP response, it stores the incoming headers so that they can be accessed later via the libcurl headers API. However, curl did not have a limit in how many or how large headers it would accept in a response, allowing a malicious server to stream an endless series of headers and eventually cause curl to run out of heap memory.
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CVE-2024-2511
Issue summary: Some non-default TLS server configurations can cause unbounded memory growth when processing TLSv1.3 sessions Impact summary: An attacker may exploit certain server configurations to trigger unbounded memory growth that would lead to a Denial of Service This problem can occur in TLSv1.3 if the non-default SSL_OP_NO_TICKET option is being used (but not if early_data support is also configured and the default anti-replay protection is in use). In this case, under certain conditions, the session cache can get into an incorrect state and it will fail to flush properly as it fills. The session cache will continue to grow in an unbounded manner. A malicious client could deliberately create the scenario for this failure to force a Denial of Service. It may also happen by accident in normal operation. This issue only affects TLS servers supporting TLSv1.3. It does not affect TLS clients. The FIPS modules in 3.2, 3.1 and 3.0 are not affected by this issue. OpenSSL 1.0.2 is also not affected by this issue.
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CVE-2020-7046
lib-smtp in submission-login and lmtp in Dovecot 2.3.9 before 2.3.9.3 mishandles truncated UTF-8 data in command parameters, as demonstrated by the unauthenticated triggering of a submission-login infinite loop.
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CVE-2021-4044
Internally libssl in OpenSSL calls X509_verify_cert() on the client side to verify a certificate supplied by a server. That function may return a negative return value to indicate an internal error (for example out of memory). Such a negative return value is mishandled by OpenSSL and will cause an IO function (such as SSL_connect() or SSL_do_handshake()) to not indicate success and a subsequent call to SSL_get_error() to return the value SSL_ERROR_WANT_RETRY_VERIFY. This return value is only supposed to be returned by OpenSSL if the application has previously called SSL_CTX_set_cert_verify_callback(). Since most applications do not do this the SSL_ERROR_WANT_RETRY_VERIFY return value from SSL_get_error() will be totally unexpected and applications may not behave correctly as a result. The exact behaviour will depend on the application but it could result in crashes, infinite loops or other similar incorrect responses. This issue is made more serious in combination with a separate bug in OpenSSL 3.0 that will cause X509_verify_cert() to indicate an internal error when processing a certificate chain. This will occur where a certificate does not include the Subject Alternative Name extension but where a Certificate Authority has enforced name constraints. This issue can occur even with valid chains. By combining the two issues an attacker could induce incorrect, application dependent behaviour. Fixed in OpenSSL 3.0.1 (Affected 3.0.0).
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CVE-2019-5645
By sending a specially crafted HTTP GET request to a listening Rapid7 Metasploit HTTP handler, an attacker can register an arbitrary regular expression. When evaluated, this malicious handler can either prevent new HTTP handler sessions from being established, or cause a resource exhaustion on the Metasploit server.
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CVE-2024-45802
Squid is an open source caching proxy for the Web supporting HTTP, HTTPS, FTP, and more. Due to Input Validation, Premature Release of Resource During Expected Lifetime, and Missing Release of Resource after Effective Lifetime bugs, Squid is vulnerable to Denial of Service attacks by a trusted server against all clients using the proxy. This bug is fixed in the default build configuration of Squid version 6.10.
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CVE-2022-31698
The vCenter Server contains a denial-of-service vulnerability in the content library service. A malicious actor with network access to port 443 on vCenter Server may exploit this issue to trigger a denial-of-service condition by sending a specially crafted header.
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CVE-2026-28318
SolarWinds Serv-U is susceptible to specially crafted POST requests that crash the Serv-U service without authentication using Content-Encoding: deflate. Mitigation steps are provided to secure customer environments in the SolarWinds Trust Center if you are unable to deploy the update
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CVE-2023-21887
Vulnerability in the MySQL Server product of Oracle MySQL (component: Server: GIS). Supported versions that are affected are 8.0.31 and prior. Easily exploitable vulnerability allows high privileged attacker with network access via multiple protocols to compromise MySQL Server. Successful attacks of this vulnerability can result in unauthorized ability to cause a hang or frequently repeatable crash (complete DOS) of MySQL Server. CVSS 3.1 Base Score 4.9 (Availability impacts). CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H).
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CVE-2021-2429
Vulnerability in the MySQL Server product of Oracle MySQL (component: InnoDB). Supported versions that are affected are 8.0.25 and prior. Difficult to exploit vulnerability allows unauthenticated attacker with network access via multiple protocols to compromise MySQL Server. Successful attacks of this vulnerability can result in unauthorized ability to cause a hang or frequently repeatable crash (complete DOS) of MySQL Server. CVSS 3.1 Base Score 5.9 (Availability impacts). CVSS Vector: (CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H).
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CVE-2022-32206
curl < 7.84.0 supports "chained" HTTP compression algorithms, meaning that a serverresponse can be compressed multiple times and potentially with different algorithms. The number of acceptable "links" in this "decompression chain" was unbounded, allowing a malicious server to insert a virtually unlimited number of compression steps.The use of such a decompression chain could result in a "malloc bomb", makingcurl end up spending enormous amounts of allocated heap memory, or trying toand returning out of memory errors.
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CVE-2021-42697
Akka HTTP 10.1.x before 10.1.15 and 10.2.x before 10.2.7 can encounter stack exhaustion while parsing HTTP headers, which allows a remote attacker to conduct a Denial of Service attack by sending a User-Agent header with deeply nested comments.
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CVE-2026-49975
Memory Allocation with Excessive Size Value vulnerability in Apache HTTP Server's mod_http leads to denial of service via malicious HTTP requests. This issue affects Apache HTTP Server: from 2.4.17 through 2.4.67.
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CVE-2020-11996
A specially crafted sequence of HTTP/2 requests sent to Apache Tomcat 10.0.0-M1 to 10.0.0-M5, 9.0.0.M1 to 9.0.35 and 8.5.0 to 8.5.55 could trigger high CPU usage for several seconds. If a sufficient number of such requests were made on concurrent HTTP/2 connections, the server could become unresponsive.
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CVE-2019-11253
Improper input validation in the Kubernetes API server in versions v1.0-1.12 and versions prior to v1.13.12, v1.14.8, v1.15.5, and v1.16.2 allows authorized users to send malicious YAML or JSON payloads, causing the API server to consume excessive CPU or memory, potentially crashing and becoming unavailable. Prior to v1.14.0, default RBAC policy authorized anonymous users to submit requests that could trigger this vulnerability. Clusters upgraded from a version prior to v1.14.0 keep the more permissive policy by default for backwards compatibility.
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CVE-2019-3957
Dameware Remote Mini Control version 12.1.0.34 and prior contains an unauthenticated remote buffer over-read due to the server not properly validating RsaSignatureLen during key negotiation, which could crash the application or leak sensitive information.
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CVE-2002-20001
The Diffie-Hellman Key Agreement Protocol allows remote attackers (from the client side) to send arbitrary numbers that are actually not public keys, and trigger expensive server-side DHE modular-exponentiation calculations, aka a D(HE)at or D(HE)ater attack. The client needs very little CPU resources and network bandwidth. The attack may be more disruptive in cases where a client can require a server to select its largest supported key size. The basic attack scenario is that the client must claim that it can only communicate with DHE, and the server must be configured to allow DHE.
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CVE-2019-12402
The file name encoding algorithm used internally in Apache Commons Compress 1.15 to 1.18 can get into an infinite loop when faced with specially crafted inputs. This can lead to a denial of service attack if an attacker can choose the file names inside of an archive created by Compress.
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CVE-2021-32675
Redis is an open source, in-memory database that persists on disk. When parsing an incoming Redis Standard Protocol (RESP) request, Redis allocates memory according to user-specified values which determine the number of elements (in the multi-bulk header) and size of each element (in the bulk header). An attacker delivering specially crafted requests over multiple connections can cause the server to allocate significant amount of memory. Because the same parsing mechanism is used to handle authentication requests, this vulnerability can also be exploited by unauthenticated users. The problem is fixed in Redis versions 6.2.6, 6.0.16 and 5.0.14. An additional workaround to mitigate this problem without patching the redis-server executable is to block access to prevent unauthenticated users from connecting to Redis. This can be done in different ways: Using network access control tools like firewalls, iptables, security groups, etc. or Enabling TLS and requiring users to authenticate using client side certificates.
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CVE-2021-33959
Plex media server 1.21 and before is vulnerable to ddos reflection attack via plex service.
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CVE-2025-0317
A vulnerability in ollama/ollama versions <=0.3.14 allows a malicious user to upload and create a customized GGUF model file on the Ollama server. This can lead to a division by zero error in the ggufPadding function, causing the server to crash and resulting in a Denial of Service (DoS) attack.
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CVE-2020-8616
A malicious actor who intentionally exploits this lack of effective limitation on the number of fetches performed when processing referrals can, through the use of specially crafted referrals, cause a recursing server to issue a very large number of fetches in an attempt to process the referral. This has at least two potential effects: The performance of the recursing server can potentially be degraded by the additional work required to perform these fetches, and The attacker can exploit this behavior to use the recursing server as a reflector in a reflection attack with a high amplification factor.
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CVE-2024-6036
A vulnerability in gaizhenbiao/chuanhuchatgpt version 20240410 allows any user to restart the server at will by sending a specific request to the `/queue/join?` endpoint with `"fn_index":66`. This unrestricted server restart capability can severely disrupt service availability, cause data loss or corruption, and potentially compromise system integrity.
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CVE-2024-6037
A vulnerability in gaizhenbiao/chuanhuchatgpt version 20240410 allows an attacker to create arbitrary folders at any location on the server, including the root directory (C: dir). This can lead to uncontrolled resource consumption, resulting in resource exhaustion, denial of service (DoS), server unavailability, and potential data loss or corruption.
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CVE-2021-2021
Vulnerability in the MySQL Server product of Oracle MySQL (component: Server: Optimizer). Supported versions that are affected are 8.0.22 and prior. Easily exploitable vulnerability allows high privileged attacker with network access via multiple protocols to compromise MySQL Server. Successful attacks of this vulnerability can result in unauthorized ability to cause a hang or frequently repeatable crash (complete DOS) of MySQL Server. CVSS 3.1 Base Score 4.9 (Availability impacts). CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H).
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CVE-2025-59538
Argo CD is a declarative, GitOps continuous delivery tool for Kubernetes. For versions 2.9.0-rc1 through 2.14.19, 3.0.0-rc1 through 3.2.0-rc1, 3.1.6 and 3.0.17, when the webhook.azuredevops.username and webhook.azuredevops.password are not set in the default configuration, the /api/webhook endpoint crashes the entire argocd-server process when it receives an Azure DevOps Push event whose JSON array resource.refUpdates is empty. The slice index [0] is accessed without a length check, causing an index-out-of-range panic. A single unauthenticated HTTP POST is enough to kill the process. This issue is resolved in versions 2.14.20, 3.2.0-rc2, 3.1.8 and 3.0.19.
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CVE-2020-11612
The ZlibDecoders in Netty 4.1.x before 4.1.46 allow for unbounded memory allocation while decoding a ZlibEncoded byte stream. An attacker could send a large ZlibEncoded byte stream to the Netty server, forcing the server to allocate all of its free memory to a single decoder.
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CVE-2019-0205
In Apache Thrift all versions up to and including 0.12.0, a server or client may run into an endless loop when feed with specific input data. Because the issue had already been partially fixed in version 0.11.0, depending on the installed version it affects only certain language bindings.
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CVE-2025-8761
A vulnerability has been found in INSTAR 2K+ and 4K 3.11.1 Build 1124. This vulnerability affects unknown code of the component Backend IPC Server. The manipulation leads to denial of service. The attack can be initiated remotely. The exploit has been disclosed to the public and may be used.
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CVE-2015-5230
The DNS packet parsing/generation code in PowerDNS (aka pdns) Authoritative Server 3.4.x before 3.4.6 allows remote attackers to cause a denial of service (crash) via crafted query packets.
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CVE-2020-8251
Node.js < 14.11.0 is vulnerable to HTTP denial of service (DoS) attacks based on delayed requests submission which can make the server unable to accept new connections.
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CVE-2019-0197
A vulnerability was found in Apache HTTP Server 2.4.34 to 2.4.38. When HTTP/2 was enabled for a http: host or H2Upgrade was enabled for h2 on a https: host, an Upgrade request from http/1.1 to http/2 that was not the first request on a connection could lead to a misconfiguration and crash. Server that never enabled the h2 protocol or that only enabled it for https: and did not set "H2Upgrade on" are unaffected by this issue.
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CVE-2020-10967
In Dovecot before 2.3.10.1, remote unauthenticated attackers can crash the lmtp or submission process by sending mail with an empty localpart.
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CVE-2021-2389
Vulnerability in the MySQL Server product of Oracle MySQL (component: InnoDB). Supported versions that are affected are 5.7.34 and prior and 8.0.25 and prior. Difficult to exploit vulnerability allows unauthenticated attacker with network access via multiple protocols to compromise MySQL Server. Successful attacks of this vulnerability can result in unauthorized ability to cause a hang or frequently repeatable crash (complete DOS) of MySQL Server. CVSS 3.1 Base Score 5.9 (Availability impacts). CVSS Vector: (CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H).
CVEs that affect server, sorted by how likely they are to be exploited (EPSS).