RHSA-2015:2111 — Security Advisory

Updated grep packages that fix one security issue and several bugs are now available for Red Hat Enterprise Linux 7.

Red Hat Product Security has rated this update as having Low security impact. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available from the CVE link in the References section.

The grep utility searches through textual input for lines that contain a match to a specified pattern and then prints the matching lines. The GNU grep utilities include grep, egrep, and fgrep.

A heap-based buffer overflow flaw was found in the way grep processed certain pattern and text combinations. An attacker able to trick a user into running grep on specially crafted input could use this flaw to crash grep or, potentially, read from uninitialized memory. (CVE-2015-1345)

This update also fixes the following bugs:

• Prior to this update, the \w and \W symbols were inconsistently matched to the [:alnum:] character class. Consequently, using regular expressions with "\w" and "\W" could lead to incorrect results. With this update, "\w" is consistently matched to the [[:alnum:]] character, and "\W" is consistently matched to the [^[:alnum:]] character. (BZ#1159012)

• Previously, the Perl Compatible Regular Expression (PCRE) matcher (selected by the "-P" parameter in grep) did not work correctly when matching non-UTF-8 text in UTF-8 locales. Consequently, an error message about invalid UTF-8 byte sequence characters was returned. To fix this bug, patches from upstream have been applied to the grep utility. As a result, PCRE now skips non-UTF-8 characters as non-matching text without returning any error message. (BZ#1217080)

All grep users are advised to upgrade to these updated packages, which contain backported patches to correct these issues.