SecuriTricks - CVE-2024-43802

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.

Product(s) Impacted

Product	Versions
Vim	['9.1.0697']

Weaknesses

Common security weaknesses mapped to this vulnerability.

CWE-122

Heap-based Buffer Overflow

A heap overflow condition is a buffer overflow, where the buffer that can be overwritten is allocated in the heap portion of memory, generally meaning that the buffer was allocated using a routine such as malloc().

References

https://github.com/vim/vim/commit/322ba9108612bead5eb

https://github.com/vim/vim/security/advisories/GHSA-4ghr-c62x-cqfh

CVSS Score

4.5 / 10

CVSS Data - 3.1

Attack Vector: LOCAL
Attack Complexity: HIGH
Privileges Required: NONE
Scope: UNCHANGED
Confidentiality Impact: LOW
Integrity Impact: LOW
Availability Impact: LOW

CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:L/I:L/A:L

View Vector String

Timeline

Published: Aug. 26, 2024, 7:15 p.m.
Last Modified: Aug. 27, 2024, 1:02 p.m.

Status : Awaiting Analysis

CVE has been recently published to the CVE List and has been received by the NVD.

More info

Source

security-advisories@github.com

CVE-2024-43802