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[SECURITY ADVISORY] curl bad local IPv6 connection reuse
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From: Daniel Stenberg via curl-users <curl-users_at_lists.haxx.se>
Date: Wed, 27 Apr 2022 08:42:57 +0200 (CEST)
Bad local IPv6 connection reuse
===============================
Project curl Security Advisory, April 27 2022 -
[Permalink](https://curl.se/docs/CVE-2022-27775.html)
VULNERABILITY
-------------
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 the IPv6
address zone id into account which could lead to libcurl reusing the wrong
connection when one transfer uses a zone id and a subsequent transfer uses
another (or no) zone id.
We are not aware of any exploit of this flaw.
INFO
Date: Wed, 27 Apr 2022 08:42:57 +0200 (CEST)
Bad local IPv6 connection reuse
===============================
Project curl Security Advisory, April 27 2022 -
[Permalink](https://curl.se/docs/CVE-2022-27775.html)
VULNERABILITY
-------------
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 the IPv6
address zone id into account which could lead to libcurl reusing the wrong
connection when one transfer uses a zone id and a subsequent transfer uses
another (or no) zone id.
We are not aware of any exploit of this flaw.
INFO
---- Zone ids are only used for non-global scoped IPv6 addresses and they are only used when specifying the address numerically. This flaw has existed in curl since commit [2d0e9b40d3237b1](https://github.com/curl/curl/commit/2d0e9b40d3237b1), shipped in libcurl 7.65.0, released on May 22 2019. Previous versions will instead not accept URLs with zone ids. The Common Vulnerabilities and Exposures (CVE) project has assigned the name CVE-2022-27775 to this issue. CWE-200: Exposure of Sensitive Information to an Unauthorized Actor Severity: Low AFFECTED VERSIONS ----------------- - Affected versions: curl 7.65.0 to and including 7.82.0 - Not affected versions: curl < 7.65.0 and curl >= 7.83.0 Also note that libcurl is used by many applications, and not always advertised as such. THE SOLUTION ------------ A [fix for CVE-2022-27775](https://github.com/curl/curl/commit/058f98dc3fe595f21dc26) RECOMMENDATIONS -------------- A - Upgrade curl to version 7.83.0 B - Apply the patch to your local version C - Do not use non-global numerical IPv6 addresses in URLs to curl TIMELINE -------- This issue was reported to the curl project on April 21, 2022. We contacted distros_at_openwall on April 21. libcurl 7.83.0 was released on April 27 2022, coordinated with the publication of this advisory. CREDITS ------- This issue was reported by Harry Sintonen. Patched by Daniel Stenberg. Thanks a lot! -- / daniel.haxx.se | Commercial curl support up to 24x7 is available! | Private help, bug fixes, support, ports, new features | https://curl.se/support.html -- Unsubscribe: https://lists.haxx.se/listinfo/curl-users Etiquette: https://curl.haxx.se/mail/etiquette.htmlReceived on 2022-04-27