Process crash via trunc_string out-of-bounds write
Published Oct 2, 2023 · Updated Nov 3, 2025
Heap-based buffer overflow in Vim before 9.0.1969 allows local users to crash the editor through a crafted file. The trunc_string() function in src/message.c writes a NUL byte to buf[e-1] when e can exceed buflen, causing a one-byte heap out-of-bounds write. Exploitation requires Vim to process attacker-controlled content and can terminate the Vim process without reported data disclosure or modification.
Summary
What happened
Heap-based buffer overflow in Vim before 9.0.1969 allows local users to crash the editor through a crafted file. The trunc_string() function in src/message.c writes a NUL byte to buf[e-1] when e can exceed buflen, causing a one-byte heap out-of-bounds write. Exploitation requires Vim to process attacker-controlled content and can terminate the Vim process without reported data disclosure or modification.
The record
- CVE
- CVE-2023-5344
- Published
- Oct 2, 2023
- Updated
- Nov 3, 2025
- Vendor
- Vim
- Product
- Vim
- Classifications
- CWE-122, CWE-787, T1499
- Attack vector
- local
- Privileges
- unauthenticated
Timeline
How it unfolded
- Oct 2, 2023CVE publishedPublication date reported by the CVE source.
- Nov 3, 2025Record 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 <9.0.1969
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
- vim_msg_trunc_poc regression corpusproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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