A flaw has been found in the host_aton() function, which can overflow a buffer if it is presented with an illegal IPv6 address that has more than 8 components. When supplying certain command line parameters, the input was not checked, so that a local attacker could possibly exploit the buffer overflow to run arbitrary code with the privileges of the Exim mail server. (CAN-2005-0021)
Additionally, the BASE64 decoder in the SPA authentication handler did not check the size of its output buffer. By sending an invalid BASE64 authentication string, a remote attacker could overflow the buffer, which could possibly be exploited to run arbitrary code with the privileges of the Exim mail server. (CAN-2005-0022)
7 January 2005
A security issue affects these releases of Ubuntu and its derivatives:
A flaw has been found in the host_aton() function, which can overflow a buffer if it is presented with an illegal IPv6 address that has more than 8 components. When supplying certain command line parameters, the input was not checked, so that a local attacker could possibly exploit the buffer overflow to run arbitrary code with the privileges of the Exim mail server. (CAN-2005-0021)
Additionally, the BASE64 decoder in the SPA authentication handler did not check the size of its output buffer. By sending an invalid BASE64 authentication string, a remote attacker could overflow the buffer, which could possibly be exploited to run arbitrary code with the privileges of the Exim mail server. (CAN-2005-0022)
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.
Vulmon