CVE-2019-16791 — In postfix-mta-sts-resolver before 0

In postfix-mta-sts-resolver before 0.5.1, All users can receive incorrect response from daemon under rare conditions, rendering downgrade of effective STS policy.

01What is this vulnerability?

In postfix-mta-sts-resolver before 0.5.1, All users can receive incorrect response from daemon under rare conditions, rendering downgrade of effective STS policy.

02Affected products

Vendor	Product	Versions
Snawoot	postfix	mta-sts-resolver — < 0.5.1

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: 2020-01-22T01:40:14.000Z
• Last modified: 2024-08-05T01:24:47.238Z

09References

• github.com — https://github.com/Snawoot/postfix-mta-sts-resolver/security/advisories/GHSA-h92…
• gist.github.com — https://gist.github.com/Snawoot/b9da85d6b26dea5460673b29df1adc6b