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.
Conclusion & alert: CVE-2020-12872 is rated Exploit Available (50/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.39%). Core evidence: 1 public exploit reference(s) are indexed (Exploit-DB). Mandatory action: Public exploits are available—assess exposure, apply mitigations, and prioritize patching.
Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.
| EDB-ID | Source | Kind | Published | Link |
|---|---|---|---|---|
| — | nvd_ref | exploit_tag | Exploit-DB ↗ |
EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).
| # | Date | Old EPSS score | New EPSS score | Delta (New - Old) |
|---|---|---|---|---|
| 1 | 2026-06-15 | 0.03% | 0.39% | +0.36% |
| 2 | 2026-02-18 | 0.11% | 0.03% | -0.08% |
| 3 | 2025-11-21 | — | 0.11% | — |
Full EPSS history (13 records total)
CVSS metrics for this CVE.
| Base score | Version | Severity | Vector | Exploitability | Impact | Score source |
|---|---|---|---|---|---|---|
| 5.5 | 3.1 | MEDIUM |
|
1.8 | 3.6 | [email protected] |
| 2.1 | 2.0 | LOW |
|
3.9 | 2.9 | [email protected] |
| vendor | priority | summary | link |
|---|---|---|---|
debian
|
low | CVE-2020-12872 low priority: Debian including 1 source packages (erlang), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. | https://security-tracker.debian.org/tracker/CVE-2020-12872 |
ubuntu
|
low | CVE-2020-12872 low priority: Ubuntu including 1 source packages (yaws), 17 status rows across 17 suites (bionic, eoan, focal, groovy, hirsute, impish, jammy, kinetic, lunar, mantic, noble, oracular, plucky, questing, trusty, upstream, xenial): ignored 9, needs-triage 7, DNE 1. | https://ubuntu.com/security/CVE-2020-12872 |
| URL | Tags |
|---|---|
| https://github.com/erlyaws/yaws/blob/c0fd79f17d52628fcec527da7fa3e788c283c445/src/yaws_config.erl#L2068-L2075 | Exploit Third Party Advisory |
| https://github.com/erlyaws/yaws/issues/402 | Issue Tracking Third Party Advisory |
| https://github.com/erlyaws/yaws/releases | Release Notes Third Party Advisory |
| https://medium.com/%40charlielabs101/cve-2020-12872-df315411aa70 | |
| https://sweet32.info/ | Third Party Advisory |