Bug 1981460 (CVE-2021-22924) - CVE-2021-22924 curl: Bad connection reuse due to flawed path name checks
Summary: CVE-2021-22924 curl: Bad connection reuse due to flawed path name checks
Alias: CVE-2021-22924
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
Target Milestone: ---
Assignee: Red Hat Product Security
QA Contact:
Depends On: 1983588 1983589 1982730 1982731 1983586 1983587 1983590 1984327 1984716 1984717 1990586 1990587
Blocks: 1981436
TreeView+ depends on / blocked
Reported: 2021-07-12 15:27 UTC by Marian Rehak
Modified: 2022-04-17 21:29 UTC (History)
42 users (show)

Fixed In Version: curl 7.78.0
Doc Type: If docs needed, set a value
Doc Text:
A flaw was found in libcurl in the way libcurl handles previously used connections without accounting for 'issuer cert' and comparing the involved paths case-insensitively. This flaw allows libcurl to use the wrong connection. The highest threat from this vulnerability is to confidentiality.
Clone Of:
Last Closed: 2021-09-21 18:21:20 UTC

Attachments (Terms of Use)

System ID Private Priority Status Summary Last Updated
Red Hat Product Errata RHSA-2021:3582 0 None None None 2021-09-21 08:40:49 UTC
Red Hat Product Errata RHSA-2022:1354 0 None None None 2022-04-13 14:29:04 UTC

Description Marian Rehak 2021-07-12 15:27:36 UTC
libcurl keeps previously used connections in a connection pool for subsequent transfers to reuse, if one of them matches the setup. Due to errors in the logic, the config matching function did not take 'issuer cert' into account and it compared the involved paths *case insensitively*, which could lead to libcurl reusing wrong connections. File paths are, or can be, case sensitive on many systems but not all, and can even vary depending on used file systems. The comparison also didn't include the 'issuer cert' which a transfer can set to qualify how to verify the server certificate.

Comment 5 Marian Rehak 2021-07-21 09:14:11 UTC
Created curl tracking bugs for this issue:

Affects: fedora-all [bug 1984327]

Comment 9 Tomas Hoger 2021-08-25 14:19:09 UTC
Upstream advisory:


Comment 10 errata-xmlrpc 2021-09-21 08:40:45 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8

Via RHSA-2021:3582 https://access.redhat.com/errata/RHSA-2021:3582

Comment 11 Product Security DevOps Team 2021-09-21 18:21:20 UTC
This bug is now closed. Further updates for individual products will be reflected on the CVE page(s):


Comment 13 errata-xmlrpc 2022-04-13 14:29:00 UTC
This issue has been addressed in the following products:

  .NET Core on Red Hat Enterprise Linux

Via RHSA-2022:1354 https://access.redhat.com/errata/RHSA-2022:1354

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