SMTP command injection via uncleared pre-TLS buffer
Published May 18, 2024 · Updated Aug 2, 2024
SMTP command injection in aio-libs aiosmtpd before 1.4.6 allows man-in-the-middle attackers to submit plaintext commands as TLS-protected input. The STARTTLS transport upgrade in aiosmtpd/smtp.py leaves queued plaintext in StreamReader._buffer, so the new TLS session consumes it as trusted post-upgrade input. An unauthenticated attacker positioned between an SMTP client and server can inject commands into the client's authenticated session, affecting message confidentiality and integrity without interrupting service.
Summary
What happened
SMTP command injection in aio-libs aiosmtpd before 1.4.6 allows man-in-the-middle attackers to submit plaintext commands as TLS-protected input. The STARTTLS transport upgrade in aiosmtpd/smtp.py leaves queued plaintext in StreamReader._buffer, so the new TLS session consumes it as trusted post-upgrade input. An unauthenticated attacker positioned between an SMTP client and server can inject commands into the client's authenticated session, affecting message confidentiality and integrity without interrupting service.
The record
- CVE
- CVE-2024-34083
- Published
- May 18, 2024
- Updated
- Aug 2, 2024
- Vendor
- aio-libs
- Product
- aiosmtpd
- Classifications
- CWE-349, T1557
- Attack vector
- adjacent
- Privileges
- unauthenticated
Timeline
How it unfolded
- May 18, 2024CVE publishedPublication date reported by the CVE source.
- Aug 2, 2024Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=0 <1.4.6
- Affected versionversion=< 1.4.6
What conditions does exploitation require?
What is affected?
Published CVSS scores
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Attacks
What attackers are doing with it
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Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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