CVE-2020-12872 — yaws_config

yaws_config.erl in Yaws through 2.0.2 and/or 2.0.7 loads obsolete TLS ciphers, as demonstrated by ones that allow Sweet32 attacks, if running on an Erlang/OTP virtual machine with a version less than 21.0.

01What is this vulnerability?

yaws_config.erl in Yaws through 2.0.2 and/or 2.0.7 loads obsolete TLS ciphers, as demonstrated by ones that allow Sweet32 attacks, if running on an Erlang/OTP virtual machine with a version less than 21.0.

02Affected products

Vendor	Product	Versions
n	a / n/a	n/a

03Active exploitation status

Not currently listed on the CISA Known Exploited Vulnerabilities (KEV) catalog. EPSS is the best forward-looking signal — see the EPSS row above.

04Recommended remediation

• Patch to a fixed version listed in the vendor advisory (see references below).
• Mitigate with WAF rules, network egress filters, or feature flags where the patch is not yet available.
• Hunt historical logs for exploitation indicators — see Detection signatures below.

05Technical details

For the full vendor write-up, exploit chains, and reference implementations, see the references list in section 09.

06Detection signatures

Ask SARA in chat to draft a starting detection for this CVE in your stack of choice.

07Related CVEs

No directly-cited follow-up CVEs in the KB record for this advisory. The references list in section 09 carries the vendor cross-references.

08Timeline

• Published: 2020-05-15T18:20:07.000Z
• Last modified: 2024-08-04T12:11:19.145Z

09References

• sweet32.info — https://sweet32.info/
• github.com — https://github.com/erlyaws/yaws/blob/c0fd79f17d52628fcec527da7fa3e788c283c445/sr…
• github.com — https://github.com/erlyaws/yaws/releases
• medium.com — https://medium.com/%40charlielabs101/cve-2020-12872-df315411aa70
• github.com — https://github.com/erlyaws/yaws/issues/402