Root code execution via unchecked request lengths
Published Dec 17, 2021 · Updated Aug 3, 2024
Out-of-bounds write in X.Org Server before 21.1.2 and before 1.20.14 allows local users to execute arbitrary code as root. The RecordCreateContext and RecordRegisterClients handlers fail to validate request lengths, causing SwapCreateRegister to write beyond an allocated buffer. Low-privileged code execution on the target is required; successful exploitation grants root-level code execution and can compromise or crash the server.
Summary
What happened
Out-of-bounds write in X.Org Server before 21.1.2 and before 1.20.14 allows local users to execute arbitrary code as root. The RecordCreateContext and RecordRegisterClients handlers fail to validate request lengths, causing SwapCreateRegister to write beyond an allocated buffer. Low-privileged code execution on the target is required; successful exploitation grants root-level code execution and can compromise or crash the server.
The record
- CVE
- CVE-2021-4011
- Published
- Dec 17, 2021
- Updated
- Aug 3, 2024
- Vendor
- X.Org
- Product
- X.Org Server
- Classifications
- CWE-119, T1068
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Dec 17, 2021CVE publishedPublication date reported by the CVE source.
- Aug 3, 2024Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=xorg-x11-server 21.1.2, xorg-x11-server 1.20.14
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
No public exploit references are available in this record.
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Technologies
Your stack
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Your stack
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