Severity: important
Affected versions:
- Apache Tomcat 11.0.0-M1 through 11.0.1
- Apache Tomcat 10.1.0-M1 through 10.1.33
- Apache Tomcat 9.0.0.M1 through 9.0.97
Description:
Time-of-check Time-of-use (TOCTOU) Race Condition vulnerability in
Apache Tomcat.
This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.1, from
10.1.0-M1 through 10.1.33, from 9.0.0.M1 through 9.0.97.
The mitigation for CVE-2024-50379 was incomplete.
Users running Tomcat on a case insensitive file system with the default
servlet write enabled (readonly initialisation
parameter set to the non-default value of false) may need additional
configuration to fully mitigate CVE-2024-50379 depending on which
version of Java they are using with Tomcat:
- running on Java 8 or Java 11: the system property
sun.io.useCanonCaches must be explicitly set to false (it defaults
to true)
- running on Java 17: the system property sun.io.useCanonCaches, if
set, must be set to false (it defaults to false)
- running on Java 21 onwards: no further configuration is required
(the system property and the problematic cache have been removed)
Tomcat 11.0.3, 10.1.35 and 9.0.99 onwards will include checks that
sun.io.useCanonCaches is set appropriately before allowing the default
servlet to be write enabled on a case insensitive file system. Tomcat
will also set sun.io.useCanonCaches to false by default where it can.
Credit:
This vulnerability was first reported by Nacl, WHOAMI, Yemoli and
Ruozhi. (finder)
This vulnerability was independently reported with a very helpful PoC by
dawu@knownsec 404 team and Sunflower@knownsec 404 team (finder)
References:
https://www.cve.org/CVERecord?id=CVE-2024-50379
https://lists.apache.org/thread/b2b9qrgjrz1kvo4ym8y2wkfdvwoq6qbp
https://tomcat.apache.org/
https://www.cve.org/CVERecord?id=CVE-2024-56337
