USN-6885-4: Apache HTTP Server regression

7 April 2025

USN-6885-1 introduced a regression in Apache HTTP Server.

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Details

USN-6885-1 fixed a vulnerability in Apache. The patch
for CVE-2024-38474 was incomplete and caused regressions.
This update provides the fix for that issue.

Original advisory details:

Orange Tsai discovered that the Apache HTTP Server mod_rewrite module
incorrectly handled certain substitutions. A remote attacker could
possibly use this issue to execute scripts in directories not directly
reachable by any URL, or cause a denial of service. Some environments
may require using the new UnsafeAllow3F flag to handle unsafe
substitutions. (CVE-2024-38474)

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Ubuntu Pro provides ten-year security coverage to 25,000+ packages in Main and Universe repositories, and it is free for up to five machines.

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Update instructions

The problem can be corrected by updating your system to the following package versions:

Ubuntu 24.10
Ubuntu 24.04
Ubuntu 22.04
Ubuntu 20.04
Ubuntu 18.04
Ubuntu 16.04

In general, a standard system update will make all the necessary changes.

References

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