PHP is a widely-used general-purpose scripting language that is especially suited for Web development and can be embedded into HTML.
Multiple vulnerabilities have been discovered in PHP. Please review the CVE identifiers referenced below and the associated PHP release notes for details.
A context-dependent attacker could execute arbitrary code via a specially crafted string containing an HTML entity when the mbstring extension is enabled. Furthermore a remote attacker could execute arbitrary code via a specially crafted GD graphics file.
A remote attacker could also cause a Denial of Service via a malformed string passed to the json_decode() function, via a specially crafted ZIP file passed to the php_zip_make_relative_path() function, via a malformed JPEG image passed to the exif_read_data() function, or via temporary file exhaustion. It is also possible for an attacker to spoof certificates, bypass various safe_mode and open_basedir restrictions when certain criteria are met, perform Cross-site scripting attacks, more easily perform SQL injection attacks, manipulate settings of other virtual hosts on the same server via a malicious .htaccess entry when running on Apache, disclose memory portions, and write arbitrary files via a specially crafted ZIP archive. Some vulnerabilities with unknown impact and attack vectors have been reported as well.
There is no known workaround at this time.
All PHP users should upgrade to the latest version. As PHP is statically linked against a vulnerable version of the c-client library when the imap or kolab USE flag is enabled (GLSA 200911-03), users should upgrade net-libs/c-client beforehand:
# emerge --sync
# emerge --ask --oneshot --verbose ">=net-libs/c-client-2007e"
# emerge --ask --oneshot --verbose ">=dev-lang/php-5.2.12"