USN-56-1: exim4 vulnerabilities

Releases

• Ubuntu 4.10

Details

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)

Update instructions

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

Ubuntu 4.10

• exim4-daemon-heavy -
• exim4-daemon-light -

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

References

• CVE-2005-0022
• CVE-2005-0021