Multiple security issues have been found in Icedove, Debian's version of the Mozilla Thunderbird mail and news client: multiple memory safety errors, buffer overflows, missing permission checks, out of bound reads, use-after-frees and other implementation errors may lead to the execution of arbitrary code, privilege escalation, cross-site scripting or denial of service.
For the stable distribution (wheezy), these problems have been fixed in version 24.5.0-1~deb7u1.
For the testing distribution (jessie), these problems have been fixed in version 24.5.0-1.
For the unstable distribution (sid), these problems have been fixed in version 24.5.0-1.
We recommend that you upgrade your icedove packages.