CVE-2020-12457 json
An issue was discovered in wolfSSL before 4.5.0.
published 2020-08-21 6 y ago modified 2026-06-17 4 mo ago also EUVD-2020-4768
- cvss
- 7.5
- version 3.1, NVD
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 1.5%
- EPSS 1.5% chance of exploitation in 30 days, percentile 74%
- public exploits
- 0
- none known
Summary
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.
Patch / fix
- wolfssl wolfssl 4.5.0
- wolfssl Debian 13, Debian 12 4.5.0+dfsg-1
debian advisories DEBIAN-CVE-2020-12457
- github.com/wolfSSL/wolfssl#2927 pull request
- github.com/wolfSSL/wolfssl/releases/tag/v4.5.0-stable release
Exploit prediction
1.53% chance of exploitation in the next 30 days, higher than 74% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| NVD | 3.1 | 7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
| NVD | 2.0 | 5.0 | AV:N/AC:L/Au:N/C:N/I:N/A:P |
Classification
- Weakness
-
- CWE-835 Loop with Unreachable Exit Condition
References
-
github.com
/wolfSSL/wolfssl/pull/2927
patch, third-party-advisory
-
github.com
/wolfSSL/wolfssl/releases/tag/v4.5.0-stable
third-party-advisory
Sources
- CVE List CVE-2020-12457
- NVD CVE-2020-12457
Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.