PT-2022-11288 · Glibc+3 · Glibc+3

Untaman · Published 2021-09-07 · Updated 2025-09-04 · CVE-2021-40647

Positive Technologies (AI Summary)

CVSS v3.1

5.5

Medium

Base vector

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

Name of the Vulnerable Software and Affected Versions man2html version 1.6g GLIBC versions prior to 2.29

Description A specific string read from a file can overwrite the size parameter in the top chunk of the heap, causing a segmentation abort if the heap size parameter is not aligned correctly. In versions before GLIBC 2.29, and when aligned correctly, this allows arbitrary write access anywhere in the program's memory.

Recommendations For man2html version 1.6g, consider updating to a version that uses GLIBC version 2.29 or later to mitigate the risk. For GLIBC versions prior to 2.29, as a temporary workaround, consider restricting access to files that could contain the specific string, until a patch is available.

Exploit

Fix

Memory Corruption

Weakness Enumeration

CWE-787

Related Identifiers

BDU:2025-11258

CVE-2021-40647

MGASA-2025-0097

Affected Products

Debian

Glibc

Red Os

Man2Html

References · 19

• 🔥 https://gist.github.com/untaman/cb58123fe89fc65e3984165db5d40933 · Exploit
• https://ubuntu.com/security/CVE-2021-40647 · Vendor Advisory
• https://osv.dev/vulnerability/DEBIAN-CVE-2021-40647 · Vendor Advisory
• https://osv.dev/vulnerability/CVE-2021-40647 · Vendor Advisory
• https://osv.dev/vulnerability/UBUNTU-CVE-2021-40647 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2021-40647 · Security Note
• https://security-tracker.debian.org/tracker/CVE-2021-40647 · Vendor Advisory
• http://repo.red-soft.ru/redos/7.3c/x86_64/updates · Vendor Advisory
• https://cve.org/CVERecord?id=CVE-2021-40647 · Security Note
• https://osv.dev/vulnerability/MGASA-2025-0097 · Vendor Advisory
• https://advisories.mageia.org/MGASA-2025-0097.html · Security Note
• https://bdu.fstec.ru/vul/2025-11258 · Security Note
• https://lists.fedoraproject.org/archives/list/[e-mail]/message/BAS4Z6KUDJQV22DP5BTQX56WVFT3FF32 · Vendor Advisory
• https://bodhi.fedoraproject.org/updates/FEDORA-2025-538f2e492d · Note
• https://t.me/cibsecurity/49559 · Telegram Post