Antivirus bypass via malformed base64 MIME attachments
Published Nov 2, 2022 · Updated Oct 22, 2024
Insufficient authenticity verification in Fortinet AV Engine 6.2.168 and earlier and 6.4.274 and earlier allows attackers to bypass scanning. The MIME attachment parser accepts base64 content containing junk and extra padding characters, so crafted content evades antivirus inspection. Delivery of a crafted MIME attachment and user interaction are required, and the bounded consequence is missed malware detection rather than direct code execution.
Summary
What happened
Insufficient authenticity verification in Fortinet AV Engine 6.2.168 and earlier and 6.4.274 and earlier allows attackers to bypass scanning. The MIME attachment parser accepts base64 content containing junk and extra padding characters, so crafted content evades antivirus inspection. Delivery of a crafted MIME attachment and user interaction are required, and the bounded consequence is missed malware detection rather than direct code execution.
The record
- CVE
- CVE-2022-26122
- Published
- Nov 2, 2022
- Updated
- Oct 22, 2024
- Vendor
- Unknown vendor
- Product
- Unknown product
- Classifications
- CWE-345, T1027
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Nov 2, 2022CVE publishedPublication date reported by the CVE source.
- Oct 22, 2024Record updatedLatest update available in the CVE record.
Exploitability
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What is affected?
Affected products and versions are unavailable in this record.
Published CVSS scores
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Attacks
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Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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