Vulnerability identifier: #VU43654

Vulnerability risk: Medium

CVSSv3.1: 4.8 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N/E:P/RL:O/RC:C]

CVE-ID: CVE-2011-1398

CWE-ID: CWE-20

Exploitation vector: Network

Exploit availability: Yes

Vulnerable software:
PHP
Universal components / Libraries / Scripting languages

Vendor: PHP Group

Description

The vulnerability allows a remote non-authenticated attacker to manipulate data.

The sapi_header_op function in main/SAPI.c in PHP before 5.3.11 and 5.4.x before 5.4.0RC2 does not check for %0D sequences (aka carriage return characters), which allows remote attackers to bypass an HTTP response-splitting protection mechanism via a crafted URL, related to improper interaction between the PHP header function and certain browsers, as demonstrated by Internet Explorer and Google Chrome.

Mitigation
Install update from vendor's website.

Vulnerable software versions

PHP: 5.3.0 - 5.3.9

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External links
http://article.gmane.org/gmane.comp.php.devel/70584
http://lists.opensuse.org/opensuse-security-announce/2013-08/msg00006.html
http://openwall.com/lists/oss-security/2012/08/29/5
http://openwall.com/lists/oss-security/2012/09/05/15
http://rhn.redhat.com/errata/RHSA-2013-1307.html
http://secunia.com/advisories/55078
http://security-tracker.debian.org/tracker/CVE-2011-1398
http://www.securitytracker.com/id?1027463
http://www.ubuntu.com/usn/USN-1569-1
http://bugs.php.net/bug.php?id=60227

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Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability. However, proof of concept for this vulnerability is available.