Buffer overflow in Wolfssl
CVE-2019-18840
In wolfSSL 4.1.0 through 4.2.0c, there are missing sanity checks of memory accesses in parsing ASN.1 certificate data while handshaking. Specifically, there is a one-byte heap-based buffer overflow inside the DecodedCert structure in GetName in wolfcrypt/src/asn.c because the domain name location index is mishandled. Because a pointer is overwritten, there is an invalid free.
Vulnerability class: Buffer Overflow
EPSS: 0.020 (78.4th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
Affected products
- Wolfssl
- N/a — versions n/a
Weakness classification (CWE)
References
- cve@mitre.org (Exploit, Third Party Advisory, x_refsource_MISC)
Frequently asked questions
- What is CVE-2019-18840?
- CVE-2019-18840 is a high-severity vulnerability in Wolfssl, classified under Out-of-bounds Write. CVSS score: 7.5/10. Published 2019-11-09.
- How severe is CVE-2019-18840?
- High severity. CVSS v3 base score is 7.5 out of 10.