CVE-2018-20843
What it is
In libexpat in Expat before 2.2.7, XML input including XML names that contain a large number of colons could make the XML parser consume a high amount of RAM and CPU resources while processing (enough to be usable for denial-of-service attacks).
At a glance
- Exploitability
- Can be exploited over the network without logging in. High risk of service disruption.
- Exploit odds
- 7.1% chance of exploitation in the next 30 days (EPSS).
- 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: 7.1% in the next 30 days (EPSS).
- Severity: 7.5 HIGH (CVSS).
- Fix: a patch or advisory is linked.
Details
- Published
- Last modified
- Exploit probability
- 7.1% · EPSS, next 30 days
- Weakness
- CWE-611 · XML external entity
- Record status
- Modified
Affected
- Libexpat Project Libexpat < 2.2.7
- Canonical Ubuntu Linux 12.04
- Canonical Ubuntu Linux 14.04
- Canonical Ubuntu Linux 16.04
- Canonical Ubuntu Linux 18.04
- Canonical Ubuntu Linux 18.10
- Canonical Ubuntu Linux 19.04
- Debian Linux 8.0
Attack profile CVSS 3.1 · 7.5
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- None
- Availability
- High
Raw vector
CVSS:3.1/AV:N/AC:L/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-2018-20843.md and follow it. Check whether this project is affected by CVE-2018-20843. 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://github.com/libexpat/libexpat/issues/186
- https://github.com/libexpat/libexpat/pull/262
- https://github.com/libexpat/libexpat/pull/262/commits/11f8838bf99ea0a6f0b76f9760c43704d00c4ff6
- https://www.oracle.com/security-alerts/cpuApr2021.html
- https://www.oracle.com/security-alerts/cpuapr2020.html
- https://www.oracle.com/security-alerts/cpuoct2020.html
- https://www.oracle.com/security-alerts/cpuoct2021.html
- https://github.com/libexpat/libexpat/issues/186
- https://github.com/libexpat/libexpat/pull/262
- https://github.com/libexpat/libexpat/pull/262/commits/11f8838bf99ea0a6f0b76f9760c43704d00c4ff6
References
- http://lists.opensuse.org/opensuse-security-announce/2019-07/msg00039.html
- https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=5226
- https://github.com/libexpat/libexpat/blob/R_2_2_7/expat/Changes
- https://github.com/libexpat/libexpat/issues/186
- https://github.com/libexpat/libexpat/pull/262
- https://github.com/libexpat/libexpat/pull/262/commits/11f8838bf99ea0a6f0b76f9760c43704d00c4ff6
- https://lists.debian.org/debian-lts-announce/2019/06/msg00028.html
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/CEJJSQSG3KSUQY4FPVHZ7ZTT7FORMFVD/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/IDAUGEB3TUP6NEKJDBUBZX7N5OAUOOOK/
- https://seclists.org/bugtraq/2019/Jun/39
- https://security.gentoo.org/glsa/201911-08
- https://security.netapp.com/advisory/ntap-20190703-0001/
- https://support.f5.com/csp/article/K51011533
- https://usn.ubuntu.com/4040-1/
- https://usn.ubuntu.com/4040-2/
- https://www.debian.org/security/2019/dsa-4472
- https://www.oracle.com/security-alerts/cpuApr2021.html
- https://www.oracle.com/security-alerts/cpuapr2020.html
- https://www.oracle.com/security-alerts/cpuoct2020.html
- https://www.oracle.com/security-alerts/cpuoct2021.html
- https://www.tenable.com/security/tns-2021-11
- http://lists.opensuse.org/opensuse-security-announce/2019-07/msg00039.html
- https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=5226
- https://github.com/libexpat/libexpat/blob/R_2_2_7/expat/Changes
- https://github.com/libexpat/libexpat/issues/186