Multiple security issues have been found in Icedove, Debian’s version of
the Mozilla Thunderbird mail and news client: Multiple memory safety
errors and use-after-frees may lead to the execution of arbitrary code
or denial of service.
For the stable distribution (wheezy), these problems have been fixed in
version 24.8.0-1~deb7u1.
For the unstable distribution (sid), these problems will be fixed soon.
We recommend that you upgrade your icedove packages.