CVE-2024-43802

heap-buffer-overflow in ins_typebuf() in Vim < 9.1.0697

Published Aug 26, 2024 CVSS 3.1 · 4.5 Medium EPSS < 1% KEV · Not listed
Description
Vim is an improved version of the unix vi text editor. When flushing the typeahead buffer, Vim moves the current position in the typeahead buffer but does not check whether there is enough space left in the buffer to handle the next characters. So this may lead to the tb_off position within the typebuf variable to point outside of the valid buffer size, which can then later lead to a heap-buffer overflow in e.g. ins_typebuf(). Therefore, when flushing the typeahead buffer, check if there is enough space left before advancing the off position. If not, fall back to flush current typebuf contents. It's not quite clear yet, what can lead to this situation. It seems to happen when error messages occur (which will cause Vim to flush the typeahead buffer) in comnination with several long mappgins and so it may eventually move the off position out of a valid buffer size. Impact is low since it is not easily reproducible and requires to have several mappings active and run into some error condition. But when this happens, this will cause a crash. The issue has been fixed as of Vim patch v9.1.0697. Users are advised to upgrade. There are no known workarounds for this issue.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Debian DLA Debian DLA DLA-4097-1 vim security update
EUVD EUVD EUVD-2024-40456 Vim is an improved version of the unix vi text editor. When flushing the typeahead buffer, Vim moves the current position in the typeahead buffer but does not check whether there is enough space left in the buffer to handle the next characters. So this may lead to the tb_off position within the typebuf variable to point outside of the valid buffer size, which can then later lead to a heap-buffer overflow in e.g. ins_typebuf(). Therefore, when flushing the typeahead buffer, check if there is enough space left before advancing the off position. If not, fall back to flush current typebuf contents. It's not quite clear yet, what can lead to this situation. It seems to happen when error messages occur (which will cause Vim to flush the typeahead buffer) in comnination with several long mappgins and so it may eventually move the off position out of a valid buffer size. Impact is low since it is not easily reproducible and requires to have several mappings active and run into some error condition. But when this happens, this will cause a crash. The issue has been fixed as of Vim patch v9.1.0697. Users are advised to upgrade. There are no known workarounds for this issue.
Ubuntu USN Ubuntu USN USN-7048-1 Vim vulnerability
Ubuntu USN Ubuntu USN USN-7048-2 Vim vulnerability
History
Type Values Removed Values Added
Metrics epss

{'score': 0.0005}

epss

{'score': 0.00055}

Type Values Removed Values Added
Metrics threat_severity

Moderate

threat_severity

Low

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
Description Vim is an improved version of the unix vi text editor. When flushing the typeahead buffer, Vim moves the current position in the typeahead buffer but does not check whether there is enough space left in the buffer to handle the next characters. So this may lead to the tb_off position within the typebuf variable to point outside of the valid buffer size, which can then later lead to a heap-buffer overflow in e.g. ins_typebuf(). Therefore, when flushing the typeahead buffer, check if there is enough space left before advancing the off position. If not, fall back to flush current typebuf contents. It's not quite clear yet, what can lead to this situation. It seems to happen when error messages occur (which will cause Vim to flush the typeahead buffer) in comnination with several long mappgins and so it may eventually move the off position out of a valid buffer size. Impact is low since it is not easily reproducible and requires to have several mappings active and run into some error condition. But when this happens, this will cause a crash. The issue has been fixed as of Vim patch v9.1.0697. Users are advised to upgrade. There are no known workarounds for this issue.
Title heap-buffer-overflow in ins_typebuf() in Vim < 9.1.0697
Weaknesses CWE-122
References
Metrics cvssV3_1

{'score': 4.5, 'vector': 'CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:L/I:L/A:L'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
Nov 3, 2025, 8:38 PM
Reserved
Aug 16, 2024, 2:20 PM
Status
Deferred
Published
Aug 26, 2024, 7:15 PM
Modified
Jun 17, 2026, 7:51 AM
Severity
Low
Public date
Aug 26, 2024, 7:15 PM