The redirection implementation in parse.y in GNU Bash through 4.3 bash43-026 allows remote attackers to cause a denial of service (out-of-bounds array access and application crash) or possibly have unspecified other impact via crafted use of here documents, aka the "redir_stack" issue.

Affected: Ubuntu:14.04:LTS: bash

Florian Weimer and Todd Sabin discovered that the Bash parser incorrectly handled memory. An attacker could possibly use this issue to bypass certain environment restrictions and execute arbitrary code. (CVE-2014-7186, CVE-2014-7187)

In addition, this update introduces a hardening measure which adds prefixes and suffixes around environment variable names which contain shell functions.