PHP 5.3.27/5.4.17/5.5.1 SSL Module subjectAltNames input validation

CVSS Meta Temp Score
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CTI Interest Score
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6.6$0-$5k0.00

Summaryinfo

A vulnerability has been found in PHP 5.3.27/5.4.17/5.5.1 and classified as critical. Impacted is an unknown function of the component SSL Module. The manipulation of the argument subjectAltNames with the input %00 as part of NULL Byte leads to input validation. This vulnerability is documented as CVE-2013-4248. Additionally, an exploit exists. To fix this issue, it is recommended to deploy a patch.

Detailsinfo

A vulnerability was found in PHP 5.3.27/5.4.17/5.5.1 (Programming Language Software). It has been rated as critical. This issue affects an unknown part of the component SSL Module. The manipulation of the argument subjectAltNames with the input value %00 leads to a input validation vulnerability. Using CWE to declare the problem leads to CWE-20. The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly. Impacted is confidentiality, integrity, and availability. The summary by CVE is:

The openssl_x509_parse function in openssl.c in the OpenSSL module in PHP before 5.4.18 and 5.5.x before 5.5.2 does not properly handle a \0 character in a domain name in the Subject Alternative Name field of an X.509 certificate, which allows man-in-the-middle attackers to spoof arbitrary SSL servers via a crafted certificate issued by a legitimate Certification Authority, a related issue to CVE-2009-2408.

The weakness was released 08/14/2013 as handling of certs with null bytes as confirmed git commit (GIT Repository). It is possible to read the advisory at git.php.net. The vendor was not involved in the public release. The identification of this vulnerability is CVE-2013-4248 since 06/12/2013. The attack may be initiated remotely. No form of authentication is needed for a successful exploitation. Technical details as well as a public exploit are known.

A public exploit has been developed by Christian Heimes in SSL Cert and been published immediately after the advisory. The exploit is available at bugs.python.org. It is declared as proof-of-concept. We expect the 0-day to have been worth approximately $5k-$25k. The vulnerability scanner Nessus provides a plugin with the ID 69797 (Ubuntu 10.04 LTS / 12.04 LTS / 12.10 / 13.04 : php5 vulnerability (USN-1937-1)), which helps to determine the existence of the flaw in a target environment. It is assigned to the family Ubuntu Local Security Checks. The commercial vulnerability scanner Qualys is able to test this issue with plugin 350520 (Amazon Linux Security Advisory for php54: ALAS-2013-224).

Applying a patch is able to eliminate this problem. The bugfix is ready for download at git.php.net. A possible mitigation has been published immediately after the disclosure of the vulnerability.

The vulnerability is also documented in the databases at Tenable (69797), SecurityFocus (BID 61776†), OSVDB (96298†), Secunia (SA54480†) and Vulnerability Center (SBV-41176†). git.php.net is providing further details. Entries connected to this vulnerability are available at VDB-9956 and VDB-9978. If you want to get the best quality for vulnerability data then you always have to consider VulDB.

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CVSSv4info

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CVSSv3info

VulDB Meta Base Score: 7.3
VulDB Meta Temp Score: 6.6

VulDB Base Score: 7.3
VulDB Temp Score: 6.6
VulDB Vector: 🔍
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CVSSv2info

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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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Exploitinginfo

Class: Input validation
CWE: CWE-20
CAPEC: 🔍
ATT&CK: 🔍

Physical: No
Local: No
Remote: Yes

Availability: 🔍
Access: Public
Status: Proof-of-Concept
Author: Christian Heimes
Programming Language: 🔍
Download: 🔍

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Nessus ID: 69797
Nessus Name: Ubuntu 10.04 LTS / 12.04 LTS / 12.10 / 13.04 : php5 vulnerability (USN-1937-1)
Nessus File: 🔍
Nessus Risk: 🔍
Nessus Family: 🔍
Nessus Port: 🔍

OpenVAS ID: 892742
OpenVAS Name: Debian Security Advisory DSA 2742-1 (php5 - interpretation conflict
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Threat Intelligenceinfo

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Countermeasuresinfo

Recommended: Patch
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Patch: git.php.net
Fortigate IPS: 🔍

Timelineinfo

06/12/2013 🔍
08/14/2013 +63 days 🔍
08/14/2013 +0 days 🔍
08/14/2013 +0 days 🔍
08/14/2013 +0 days 🔍
08/14/2013 +0 days 🔍
08/16/2013 +2 days 🔍
08/17/2013 +1 days 🔍
08/21/2013 +4 days 🔍
09/06/2013 +16 days 🔍
05/21/2021 +2814 days 🔍

Sourcesinfo

Product: php.org

Advisory: handling of certs with null bytes
Status: Confirmed
Confirmation: 🔍

CVE: CVE-2013-4248 (🔍)
GCVE (CVE): GCVE-0-2013-4248
GCVE (VulDB): GCVE-100-9971

OVAL: 🔍
IAVM: 🔍

SecurityFocus: 61776 - PHP SSL Certificate Validation CVE-2013-4248 Security Bypass Vulnerability
Secunia: 54480 - PHP SSL Module "subjectAltNames" NULL Byte Handling Security Issue, Less Critical
OSVDB: 96298
SecurityTracker: 1028924
Vulnerability Center: 41176 - PHP <5.4.18 and 5.5.x - 5.5.1 OpenSSL module Remote Spoofing via Man-in-the-Middle Attack, Medium

scip Labs: https://www.scip.ch/en/?labs.20161013
Misc.: 🔍
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Entryinfo

Created: 08/16/2013 16:43
Updated: 05/21/2021 14:59
Changes: 08/16/2013 16:43 (94), 05/09/2017 10:25 (4), 05/21/2021 14:58 (3), 05/21/2021 14:59 (1)
Complete: 🔍
Cache ID: 216:087:103

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