CVE-2020-25687
What it is
A flaw was found in dnsmasq before version 2.83. A heap-based buffer overflow was discovered in dnsmasq when DNSSEC is enabled and before it validates the received DNS entries. This flaw allows a remote attacker, who can create valid DNS replies, to cause an overflow in a heap-allocated memory. This flaw is caused by the lack of length checks in rfc1035.c:extract_name(), which could be abused to make the code execute memcpy() with a negative size in sort_rrset() and cause a crash in dnsmasq, resulting in a denial of service. The highest threat from this vulnerability is to system availability.
At a glance
- Exploitability
- Can be exploited over the network without logging in. High risk of service disruption.
- Exploit odds
- 89.3% chance of exploitation in the next 30 days (EPSS). Higher than most.
- Fix
- A patch, advisory or fixed version is referenced. Upgrade or apply it.
Timeline
- PublishedDisclosed publicly on CVE.org and NVD
- Last updatedMost recent change to the record
Why it ranks here
- Exploited in the wild: no, CISA does not list it.
- Exploit odds: 89.3% in the next 30 days (EPSS).
- Severity: 5.9 MEDIUM (CVSS).
- Fix: a patch or advisory is linked.
Details
- Published
- Last modified
- Exploit probability
- 89.3% · EPSS, next 30 days
- Weakness
- CWE-122
- Record status
- Modified
Affected
- Thekelleys Dnsmasq < 2.83
- Fedoraproject Fedora 32
- Fedoraproject Fedora 33
- Debian Linux 9.0
- Debian Linux 10.0
Attack profile CVSS 3.1 · 5.9
- Attack vector
- Network
- Complexity
- High
- Privileges needed
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- None
- Availability
- High
Raw vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
Is it in your code?
Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.
Read https://cve-list.com/agent/cve/CVE-2020-25687.md and follow it. Check whether this project is affected by CVE-2020-25687. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.
Fix and advisories
- https://bugzilla.redhat.com/show_bug.cgi?id=1891568
- https://bugzilla.redhat.com/show_bug.cgi?id=1891568
References
- https://bugzilla.redhat.com/show_bug.cgi?id=1891568
- https://lists.debian.org/debian-lts-announce/2021/03/msg00027.html
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/QGB7HL3OWHTLEPSMLDGOMXQKG3KM2QME/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/WYW3IR6APUSKOYKL5FT3ACTIHWHGQY32/
- https://security.gentoo.org/glsa/202101-17
- https://www.debian.org/security/2021/dsa-4844
- https://www.jsof-tech.com/disclosures/dnspooq/
- https://bugzilla.redhat.com/show_bug.cgi?id=1891568
- https://lists.debian.org/debian-lts-announce/2021/03/msg00027.html
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/QGB7HL3OWHTLEPSMLDGOMXQKG3KM2QME/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/WYW3IR6APUSKOYKL5FT3ACTIHWHGQY32/
- https://security.gentoo.org/glsa/202101-17
- https://www.debian.org/security/2021/dsa-4844
- https://www.jsof-tech.com/disclosures/dnspooq/
- https://www.kb.cert.org/vuls/id/434904