Buffer underflow in the build_tree function in unpack.c in gzip 1.3.5 allows context-dependent attackers to execute arbitrary code via a crafted leaf count table that causes a write to a negative index.
Exploitability
AV:NAC:LAu:NImpact
C:PI:PA:P7.5/AV:N/AC:L/Au:N/C:P/I:P/A:P