PT-2021-3708 · Fortinet · Fortimail

Published 2021-06-21 · Updated 2022-07-12 · CVE-2021-24020

Positive Technologies (AI Summary)

CVSS v3.1

10

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 FortiMail versions 6.2.0 through 6.2.7 FortiMail versions 6.4.0 through 6.4.4

Description A missing cryptographic step in the implementation of the hash digest algorithm in FortiMail may allow an unauthenticated attacker to tamper with signed URLs by appending further data, which allows bypass of signature verification. This issue is related to errors in encryption in the hash algorithm, potentially enabling a remote attacker to bypass cryptographic protection mechanisms and elevate privileges.

Recommendations For FortiMail versions 6.2.0 through 6.2.7, update to a version that includes the fix for the missing cryptographic step in the hash digest algorithm implementation. For FortiMail versions 6.4.0 through 6.4.4, update to a version that includes the fix for the missing cryptographic step in the hash digest algorithm implementation. As a temporary workaround, consider restricting access to signed URLs to minimize the risk of exploitation.

Fix

Improper Verification of Cryptographic Signature

Weakness Enumeration

CWE-325

CWE-347

Related Identifiers

BDU:2021-03948

CVE-2021-24020

Affected Products

Fortimail

References · 8

• https://osv.dev/vulnerability/CVE-2021-24020 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2021-24020 · Security Note
• https://bdu.fstec.ru/vul/2021-03948 · Security Note
• https://fortiguard.com/advisory/FG-IR-21-027 · Vendor Advisory
• https://t.me/cvenotify/17455 · Telegram Post
• https://fortiguard.com/psirt/FG-IR-21-027 · Note
• https://t.me/cvenotify/17395 · Telegram Post
• https://cybersecurity-help.cz/vdb/SB2021071352 · Note