HTTPS secret disclosure via obsolete TLS ciphers
Published May 15, 2020 · Updated Aug 4, 2024
Weak TLS cipher selection in Yaws through 2.0.7 allows man-in-the-middle attackers to recover secrets from HTTPS traffic. The TLS defaults in yaws_config.erl call ssl:cipher_suites/0 and load the runtime's full cipher list, retaining obsolete 64-bit block ciphers on Erlang/OTP before 21.0. Exploitation requires a long-lived connection using a vulnerable cipher, attacker-driven authenticated traffic, and observation of the ciphertext; the bounded impact is recovery of repeated secrets such as session cookies.
Summary
What happened
Weak TLS cipher selection in Yaws through 2.0.7 allows man-in-the-middle attackers to recover secrets from HTTPS traffic. The TLS defaults in yaws_config.erl call ssl:cipher_suites/0 and load the runtime's full cipher list, retaining obsolete 64-bit block ciphers on Erlang/OTP before 21.0. Exploitation requires a long-lived connection using a vulnerable cipher, attacker-driven authenticated traffic, and observation of the ciphertext; the bounded impact is recovery of repeated secrets such as session cookies.
The record
- CVE
- CVE-2020-12872
- Published
- May 15, 2020
- Updated
- Aug 4, 2024
- Vendor
- Unknown vendor
- Product
- Unknown product
- Classifications
- T1040
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- May 15, 2020CVE 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?
What conditions does exploitation require?
What is affected?
Affected products and versions are unavailable in this record.
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
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
- Sweet32 HTTPS proof-of-concept attackproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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