An arbitrary file write vulnerability was found in GNU gzip's zgrep utility. When zgrep is applied on the attacker's chosen file name (for example, a crafted file name), this can overwrite an attacker's content to an arbitrary attacker-selected file. This flaw occurs due to insufficient validation when processing filenames with two or more newlines where selected content and the target file names are embedded in crafted multi-line file names. This flaw allows a remote, low privileged attacker to force zgrep to write arbitrary files on the system.

Integer underflow in the unlzw function in unlzw.c in gzip before 1.4 on 64-bit platforms, as used in ncompress and probably others, allows remote attackers to cause a denial of service (application crash) or possibly execute arbitrary code via a crafted archive that uses LZW compression, leading to an array index error.

The huft_build function in inflate.c in gzip before 1.3.13 creates a hufts (aka huffman) table that is too small, which allows remote attackers to cause a denial of service (application crash or infinite loop) or possibly execute arbitrary code via a crafted archive. NOTE: this issue is caused by a CVE-2006-4334 regression.