Process memory corruption via malformed lambda expression
Published Dec 19, 2021 · Updated Aug 3, 2024
Heap-based buffer overflow in Vim 8.2.2257 through 8.2.3846 allows local users to corrupt memory via a malformed lambda expression. The eval_lambda parser increments its input pointer even when a closing parenthesis is missing, advancing past the terminating NUL byte. Exploitation requires Vim to evaluate attacker-controlled malformed lambda syntax, and the resulting out-of-bounds access can crash the editor or corrupt its process.
Summary
What happened
Heap-based buffer overflow in Vim 8.2.2257 through 8.2.3846 allows local users to corrupt memory via a malformed lambda expression. The eval_lambda parser increments its input pointer even when a closing parenthesis is missing, advancing past the terminating NUL byte. Exploitation requires Vim to evaluate attacker-controlled malformed lambda syntax, and the resulting out-of-bounds access can crash the editor or corrupt its process.
The record
- CVE
- CVE-2021-4136
- Published
- Dec 19, 2021
- Updated
- Aug 3, 2024
- Vendor
- Vim
- Product
- Vim
- Classifications
- CWE-122, CWE-787, T1203
- Attack vector
- local
- Privileges
- unauthenticated
Timeline
How it unfolded
- Dec 19, 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=unspecified <8.2.3846
What conditions does exploitation require?
What is affected?
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
- Upstream malformed-lambda regression triggerproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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