The gzip package provides the GNU gzip data compression program. An integer underflow flaw, leading to an array index error, was found in the way gzip expanded archive files compressed with the Lempel-Ziv-Welch (LZW) compression algorithm. If a victim expanded a specially-crafted archive, it could cause gzip to crash or, potentially, execute arbitrary code with the privileges of the user running gzip. This flaw only affects 64-bit systems. Updated packages are available from updates.redhat.com.