fetchmail - SSL certificate verification weakness

It was discovered that fetchmail, a full-featured remote mail retrieval
and forwarding utility, is vulnerable to the “Null Prefix Attacks Against
SSL/TLS Certificates” recently published at the Blackhat conference.
This allows an attacker to perform undetected man-in-the-middle attacks
via a crafted ITU-T X.509 certificate with an injected null byte in the
subjectAltName or Common Name fields.

Note, as a fetchmail user you should always use strict certificate
validation through either these option combinations:
sslcertck ssl sslproto ssl3 (for service on SSL-wrapped ports)
or
sslcertck sslproto tls1 (for STARTTLS-based services)

For the oldstable distribution (etch), this problem has been fixed in
version 6.3.6-1etch2.

For the stable distribution (lenny), this problem has been fixed in
version 6.3.9~rc2-4+lenny1.

For the testing distribution (squeeze), this problem will be fixed soon.

For the unstable distribution (sid), this problem has been fixed in
version 6.3.9~rc2-6.

We recommend that you upgrade your fetchmail packages.