An issue was discovered in wolfSSL before 4.5.0. It mishandles the change_cipher_spec (CCS) message processing logic for TLS 1.3. If an attacker sends ChangeCipherSpec messages in a crafted way involving more than one in a row, the server becomes stuck in the ProcessReply() loop, i.e., a denial of service.
CVE-2020-12457
This high-severity CVE scores 7.5 under NVD CVSS v3. EPSS exploit probability: 1.5%, top 28% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).
- High severity, but no confirmed exploitation yet
No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.
- CVSS v3
- 7.5
- EG Score
- 7.5(medium)
- EG Risk
- 39(Track)EG Risk 39/100SSVC: Track
EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).
How it’s computedSeverity75% × 45%Exploitation2% × 40%Automatability30% × 15%Action: Routine — remediate on your standard cadence. - EPSS
- 72.1%
- KEV
- Not listed
Published
August 21, 2020
Last Modified
November 21, 2024
References (4)
- cve@mitrehttps://github.com/wolfSSL/wolfssl/pull/2927
- cve@mitrehttps://github.com/wolfSSL/wolfssl/releases/tag/v4.5.0-stable
- af854a3a-2127-422b-91ae-364da2661108https://github.com/wolfSSL/wolfssl/pull/2927
- af854a3a-2127-422b-91ae-364da2661108https://github.com/wolfSSL/wolfssl/releases/tag/v4.5.0-stable
Weakness Classification(2)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 14× in last 7d / 43× in last 30d)
Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.
- 2026-07-23 01:48 UTCEG score recompute
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Frequently asked(5)
What is CVE-2020-12457?
When was CVE-2020-12457 disclosed?
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What is the CVSS score of CVE-2020-12457?
How do I remediate CVE-2020-12457?
Dependency Blast Radius
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