Malware-check bypass via conflicting MIME boundaries
Published Mar 18, 2024 · Updated Nov 4, 2025
Interpretation conflict in Amavis before 2.12.3 and 2.13.x before 2.13.1 allows remote attackers to bypass malware checks via email. MIME::Parser selects the last of conflicting boundary parameters, while affected mail clients select the first, so Amavis scans different MIME parts. An unauthenticated sender can therefore deliver a banned or malicious attachment that reaches the recipient without an Amavis warning or block.
Summary
What happened
Interpretation conflict in Amavis before 2.12.3 and 2.13.x before 2.13.1 allows remote attackers to bypass malware checks via email. MIME::Parser selects the last of conflicting boundary parameters, while affected mail clients select the first, so Amavis scans different MIME parts. An unauthenticated sender can therefore deliver a banned or malicious attachment that reaches the recipient without an Amavis warning or block.
The record
- CVE
- CVE-2024-28054
- Published
- Mar 18, 2024
- Updated
- Nov 4, 2025
- Vendor
- Unknown vendor
- Product
- Unknown product
- Classifications
- CWE-436, T1566.001
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Mar 18, 2024CVE publishedPublication date reported by the CVE source.
- Nov 4, 2025Record 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
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Public exploit references
- Conflicting-boundary MIME message demonstrationproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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