What’s Vulnerable › Vulnerabilities

CVE-2020-15690

• Severity: critical (CVSS 9.8 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 3.2% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2021-01-30 · updated 2026-06-17
• Weakness: CWE-74

Description

In Nim before 1.2.6, the standard library asyncftpclient lacks a check for whether a message contains a newline character.

Affected products

• nim-lang Nim: before 1.2.6 — fixed in 1.2.6

How to fix

Upgrade to a fixed version: nim-lang Nim 1.2.6. Check the vendor advisory for mitigations.

References

• http://www.openwall.com/lists/oss-security/2021/02/04/3
• https://consensys.net/diligence/vulnerabilities/nim-asyncftpd-crlf-injection/
• https://github.com/nim-lang/Nim/blob/dc5a40f3f39c6ea672e6dc6aca7f8118a69dda99/lib/pure/asyncftpclient.nim#L145
• https://github.com/nim-lang/Nim/compare/v1.2.4...v1.2.6
• https://github.com/tintinweb/pub/tree/master/pocs/cve-2020-15690
• http://www.openwall.com/lists/oss-security/2021/02/04/3
• https://consensys.net/diligence/vulnerabilities/nim-asyncftpd-crlf-injection/
• https://github.com/nim-lang/Nim/blob/dc5a40f3f39c6ea672e6dc6aca7f8118a69dda99/lib/pure/asyncftpclient.nim#L145
• https://github.com/nim-lang/Nim/compare/v1.2.4...v1.2.6
• https://github.com/tintinweb/pub/tree/master/pocs/cve-2020-15690

Get alerted when CVE-2020-15690 or the next vulnerability affects your stack