Email interception via unverified SMTP certificates
Published Aug 4, 2023 · Updated Oct 8, 2024
Improper certificate validation in Matrix.org Sydent before 2.5.6 allows man-in-the-middle attackers to intercept sensitive emails. The sendEmail function calls smtplib.SMTP_SSL or starttls without an SSL context, so neither certificate trust nor hostname is checked. The attack requires TLS or STARTTLS email configuration and a privileged network position; captured messages expose room invitations, guest credentials, or address-verification tokens.
Summary
What happened
Improper certificate validation in Matrix.org Sydent before 2.5.6 allows man-in-the-middle attackers to intercept sensitive emails. The sendEmail function calls smtplib.SMTP_SSL or starttls without an SSL context, so neither certificate trust nor hostname is checked. The attack requires TLS or STARTTLS email configuration and a privileged network position; captured messages expose room invitations, guest credentials, or address-verification tokens.
The record
- CVE
- CVE-2023-38686
- Published
- Aug 4, 2023
- Updated
- Oct 8, 2024
- Vendor
- Matrix.org
- Product
- Sydent
- Classifications
- CWE-295, T1557
- Attack vector
- adjacent
- Privileges
- unauthenticated
Timeline
How it unfolded
- Aug 4, 2023CVE publishedPublication date reported by the CVE source.
- Oct 8, 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=< 2.5.6
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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Public exploit references
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Technologies
Your stack
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Your stack
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