PT-2021-2469 · Openssh+6 · Openssh+6

Published 2021-02-17 · Updated 2026-03-10 · CVE-2021-28041

Positive Technologies (AI Summary)

CVSS v3.1

7.1

High

Base vector

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

Name of the Vulnerable Software and Affected Versions OpenSSH versions prior to 8.5

Description The issue is related to a double free in ssh-agent, which may be relevant in less-common scenarios such as unconstrained agent-socket access on a legacy operating system, or the forwarding of an agent to an attacker-controlled host. This can potentially allow a remote attacker to cause a denial of service or execute arbitrary code. The problem is associated with the use of memory after it has been freed.

Recommendations For versions prior to 8.5, update to version 8.5 or later to resolve the issue. As a temporary workaround, consider restricting access to the ssh-agent to minimize the risk of exploitation.

Fix

DoS

Use After Free

Double Free

Weakness Enumeration

CWE-416

CWE-415

Related Identifiers

ALT-PU-2024-3921

ALT-PU-2024-4077

ALT-PU-2024-4467

ALT-PU-2024-9513

BDU:2021-01836

CVE-2021-28041

MGASA-2021-0261

OESA-2021-1466

OESA-2022-2083

OPENSUSE-SU-2021:4153-1

OPENSUSE-SU-2021_4153-1

OPENSUSE-SU-2024:13842-1

SUSE-SU-2021:4153-1

SUSE-SU-2021_4153-1

USN-4762-1

Affected Products

Alt Linux

Astra Linux

Linuxmint

Openssh

Red Os

Suse

Ubuntu

References · 49

• https://github.com/openssh/openssh-portable/commit/e04fd6dde16de1cdc5a4d9946397ff60d96568db · Patch
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/TXST2CML2MWY3PNVUXX7FFJE3ATJMNVZ · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2021-28041 · Security Note
• https://ubuntu.com/security/CVE-2021-28041 · Vendor Advisory
• https://lists.fedoraproject.org/archives/list/[e-mail]/message/TXST2CML2MWY3PNVUXX7FFJE3ATJMNVZ · Vendor Advisory
• http://repo.red-soft.ru/redos/7.3c/x86_64/updates · Vendor Advisory
• https://ubuntu.com/security/notices/USN-4762-1 · Vendor Advisory
• https://security-tracker.debian.org/tracker/CVE-2021-28041 · Vendor Advisory
• https://osv.dev/vulnerability/ALPINE-CVE-2021-28041 · Vendor Advisory
• https://cve.org/CVERecord?id=CVE-2021-28041 · Security Note
• https://openwall.com/lists/oss-security/2021/03/03/1 · Patch
• https://osv.dev/vulnerability/OESA-2021-1466 · Vendor Advisory
• https://openssh.com/security.html · Vendor Advisory
• https://bdu.fstec.ru/vul/2021-01836 · Security Note
• https://openssh.com/txt/release-8.5 · Vendor Advisory