Message interception via SMTP STARTTLS downgrade
Published Nov 3, 2021 · Updated Aug 4, 2024
Information disclosure in Mozilla Thunderbird before 91.2 allows remote attackers to intercept SMTP messages via a man-in-the-middle downgrade. Thunderbird ignores the account setting that requires STARTTLS, allowing a man-in-the-middle to strip TLS and control the authenticated SMTP session; unprotected authentication can reveal credentials. The attacker must occupy the network path to the SMTP server, and the demonstrated consequence is message and credential disclosure or SMTP command execution.
Summary
What happened
Information disclosure in Mozilla Thunderbird before 91.2 allows remote attackers to intercept SMTP messages via a man-in-the-middle downgrade. Thunderbird ignores the account setting that requires STARTTLS, allowing a man-in-the-middle to strip TLS and control the authenticated SMTP session; unprotected authentication can reveal credentials. The attacker must occupy the network path to the SMTP server, and the demonstrated consequence is message and credential disclosure or SMTP command execution.
The record
- CVE
- CVE-2021-38502
- Published
- Nov 3, 2021
- Updated
- Aug 4, 2024
- Vendor
- Mozilla
- Product
- Thunderbird
- Classifications
- T1557
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Nov 3, 2021CVE publishedPublication date reported by the CVE source.
- Aug 4, 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?
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- Affected versionversion=unspecified <91.2
What conditions does exploitation require?
What is affected?
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.
Weakness, pattern, technique
Public exploit references
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Your stack
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Your stack
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