Vulnerability · Published May 7, 2021 · Assigned by GitHub_M

CVE-2021-29495Nim stdlib httpClient does not validate peer certificates by default

Medium 5.9

In plain English

A medium-severity improper certificate validation in security from nim-lang. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 42% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)5.9Medium

Exploit odds (30 days)0.5%top 57.6% of all CVEs

Exploited in the wildNo reportsnot in CISA KEV

Attack toolingNoneno public tooling known

Official description

Nim is a statically typed compiled systems programming language. In Nim standard library before 1.4.2, httpClient SSL/TLS certificate verification was disabled by default. Users can upgrade to version 1.4.2 to receive a patch or, as a workaround, set "verifyMode = CVerifyPeer" as documented.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
Debian:12	nim	1.4.2-1	DEBIAN-CVE-2021-29495
Debian:14	nim	1.4.2-1	DEBIAN-CVE-2021-29495

Affected products (as reported)

Vendor	Product	Versions
nim-lang	security	< 1.4.2

Weakness: CWE-295 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N

References

https://github.com/nim-lang/security/security/advisories/GHSA-9vqv-2jj9-7mqr x_refsource_CONFIRM