PT-2021-6859 · Fortinet · Fortios

Published 2021-12-07 · Updated 2021-12-09 · CVE-2021-26109

Positive Technologies (AI Summary)

CVSS v3.1

9.8

Critical

Base vector

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

Name of the Vulnerable Software and Affected Versions FortiOS versions prior to 7.0.1

Description The issue is related to an integer overflow or wraparound vulnerability in the memory allocator of SSLVPN in FortiOS. This vulnerability may allow an unauthenticated attacker to corrupt control data on the heap via specifically crafted requests to SSLVPN, potentially resulting in arbitrary code execution.

Recommendations For versions prior to 7.0.1, update to version 7.0.1 or later to resolve the issue. As a temporary workaround, consider restricting access to the SSLVPN service until a patch is applied. Avoid using the SSLVPN service with untrusted or unknown requests until the issue is resolved.

Fix

Integer Overflow

Weakness Enumeration

CWE-190

Related Identifiers

BDU:2022-02338

CVE-2021-26109

Affected Products

Fortios

References · 9

• https://osv.dev/vulnerability/CVE-2021-26109 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2021-26109 · Security Note
• https://bdu.fstec.ru/vul/2022-02338 · Security Note
• https://safe-surf.ru/specialists/bulletins-nkcki/672904 · Security Note
• http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-26109 · Security Note
• https://fortiguard.com/advisory/FG-IR-21-049 · Vendor Advisory
• https://fortiguard.fortinet.com/psirt/FG-IR-21-049 · Note
• https://fortiguard.com/psirt/FG-IR-21-049 · Note
• https://t.me/cibsecurity/33582 · Telegram Post