Several security issues were fixed in Apache HTTP Server.
It was discovered that the Apache mod_session_crypto module was encrypting data and cookies using either CBC or ECB modes. A remote attacker could possibly use this issue to perform padding oracle attacks. (CVE-2016-0736)
9 May 2017
A security issue affects these releases of Ubuntu and its derivatives:
Several security issues were fixed in Apache HTTP Server.
It was discovered that the Apache mod_session_crypto module was encrypting data and cookies using either CBC or ECB modes. A remote attacker could possibly use this issue to perform padding oracle attacks. (CVE-2016-0736)
Maksim Malyutin discovered that the Apache mod_auth_digest module incorrectly handled malicious input. A remote attacker could possibly use this issue to cause Apache to crash, resulting in a denial of service. (CVE-2016-2161)
David Dennerline and Régis Leroy discovered that the Apache HTTP Server incorrectly handled unusual whitespace when parsing requests, contrary to specifications. When being used in combination with a proxy or backend server, a remote attacker could possibly use this issue to perform an injection attack and pollute cache. This update may introduce compatibility issues with clients that do not strictly follow HTTP protocol specifications. A new configuration option “HttpProtocolOptions Unsafe” can be used to revert to the previous unsafe behaviour in problematic environments. (CVE-2016-8743)
The problem can be corrected by updating your system to the following package versions:
To update your system, please follow these instructions: https://wiki.ubuntu.com/Security/Upgrades.
In general, a standard system update will make all the necessary changes.