CVE-2021-21373
HIGHNim < 1.2.10 - Improper Certificate Validation via Nimble Refresh Fallback
Title source: llmDescription
Nimble is a package manager for the Nim programming language. In Nim release versions before versions 1.2.10 and 1.4.4, "nimble refresh" fetches a list of Nimble packages over HTTPS by default. In case of error it falls back to a non-TLS URL http://irclogs.nim-lang.org/packages.json. An attacker able to perform MitM can deliver a modified package list containing malicious software packages. If the packages are installed and used the attack escalates to untrusted code execution.
References (3)
Core 3
Core References
Exploit, Third Party Advisory x_refsource_misc
https://consensys.net/diligence/vulnerabilities/nim-insecure-ssl-tls-defaults-remote-code-execution/
Release Notes, Third Party Advisory x_refsource_misc
https://github.com/nim-lang/nimble/blob/master/changelog.markdown#0130
Third Party Advisory x_refsource_confirm
https://github.com/nim-lang/security/security/advisories/GHSA-8w52-r35x-rgp8
Scores
CVSS v3
7.5
EPSS
0.0115
EPSS Percentile
62.9%
Attack Vector
NETWORK
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:L/I:H/A:L
Details
CWE
CWE-295
CWE-348
Status
published
Products (1)
nim-lang/nim
< 1.2.10
Published
Mar 26, 2021
Tracked Since
Feb 18, 2026