The do_uncompress function in g10/compress.c in GnuPG 1.x before 1.4.17 and 2.x before 2.0.24 allows context-dependent attackers to cause a denial of service (infinite loop) via malformed compressed packets, as demonstrated by an a3 01 5b ff byte sequence.
git.gnupg.org/cgi-bin/gitweb.cgi?p=gnupg.git%3Ba=commit%3Bh=014b2103fcb12f261135e3954f26e9e07b39e342
git.gnupg.org/cgi-bin/gitweb.cgi?p=gnupg.git%3Ba=commit%3Bh=11fdfcf82bd8d2b5bc38292a29876e10770f4b0a
lists.gnupg.org/pipermail/gnupg-announce/2014q2/000344.html
lists.gnupg.org/pipermail/gnupg-announce/2014q2/000345.html
lists.opensuse.org/opensuse-updates/2014-07/msg00010.html
secunia.com/advisories/59213
secunia.com/advisories/59351
secunia.com/advisories/59534
secunia.com/advisories/59578
www.debian.org/security/2014/dsa-2967
www.debian.org/security/2014/dsa-2968
www.oracle.com/technetwork/topics/security/bulletinapr2015-2511959.html
www.ubuntu.com/usn/USN-2258-1