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Ubuntu Security Notice USN-6885-3
September 18, 2024

apache2 vulnerabilities
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A security issue affects these releases of Ubuntu and its derivatives:

- Ubuntu 18.04 LTS
- Ubuntu 16.04 LTS

Summary:

Several security issues were fixed in Apache HTTP Server.

Software Description:
- apache2: Apache HTTP server

Details:

USN-6885-1 fixed several vulnerabilities in Apache. This update provides
the corresponding update for Ubuntu 16.04 LTS and Ubuntu 18.04 LTS.

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, CVE-2024-38475)

 Orange Tsai discovered that the Apache HTTP Server incorrectly handled
 certain response headers. A remote attacker could possibly use this issue
 to obtain sensitive information, execute local scripts, or perform SSRF
 attacks. (CVE-2024-38476)

 Orange Tsai discovered that the Apache HTTP Server mod_proxy module
 incorrectly handled certain requests. A remote attacker could possibly use
 this issue to cause the server to crash, resulting in a denial of service.
 (CVE-2024-38477)

Update instructions:

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

Ubuntu 18.04 LTS
  apache2                         2.4.29-1ubuntu4.27+esm3
                                  Available with Ubuntu Pro

Ubuntu 16.04 LTS
  apache2                         2.4.18-2ubuntu3.17+esm13
                                  Available with Ubuntu Pro

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

References:
  https://ubuntu.com/security/notices/USN-6885-3
  https://ubuntu.com/security/notices/USN-6885-2
  https://ubuntu.com/security/notices/USN-6885-1
  CVE-2024-38474, CVE-2024-38475, CVE-2024-38476, CVE-2024-38477