CVE-2020-15693

In Nim 1.2.4, the standard library httpClient is vulnerable to a CR-LF injection in the target URL. An injection is possible if the attacker controls any part of the URL provided in a call (such as httpClient.get or httpClient.post), the User-Agent header value, or custom HTTP header names or values.

• CWE-74

• http://www.openwall.com/lists/oss-security/2021/02/04/2Exploit, Mailing List, Third Party Advisory
• https://consensys.net/diligence/vulnerabilities/nim-httpclient-header-crlf-injection/Exploit, Third Party Advisory
• https://github.com/nim-lang/Nim/blob/dc5a40f3f39c6ea672e6dc6aca7f8118a69dda99/lib/pure/httpclient.nim#L1023Patch, Third Party Advisory
• https://nim-lang.org/blog/2020/07/30/versions-126-and-108-released.htmlRelease Notes, Third Party Advisory
• http://www.openwall.com/lists/oss-security/2021/02/04/2Exploit, Mailing List, Third Party Advisory
• https://consensys.net/diligence/vulnerabilities/nim-httpclient-header-crlf-injection/Exploit, Third Party Advisory
• https://github.com/nim-lang/Nim/blob/dc5a40f3f39c6ea672e6dc6aca7f8118a69dda99/lib/pure/httpclient.nim#L1023Patch, Third Party Advisory
• https://nim-lang.org/blog/2020/07/30/versions-126-and-108-released.htmlRelease Notes, Third Party Advisory

Published

Aug 14, 2020

Last Modified

Jun 17, 2026

Status

Modified

• How Strix found a critical auth bypass in etcdStrix autonomously discovered a critical authentication bypass in etcd, later designated CVE-2026-33413.
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