Debian Linux Security Advisory 3078-1 – An integer underflow flaw, leading to a heap-based buffer overflow, was found in the ksba_oid_to_str() function of libksba, an X.509 and CMS (PKCS#7) library. By using special crafted S/MIME messages or ECC based OpenPGP data, it is possible to create a buffer overflow, which could cause an application using libksba to crash (denial of service), or potentially, execute arbitrary code.