CVE-2013-6420PHP Memory Corruption
php: memory corruption in openssl_x509_parse()
Published Dec 10, 2013 · Updated Mar 9, 2026 · Also known as DEBIAN-CVE-2013-6420, DEBIAN-CVE-2013-6712, DSA-2816-1
Key Facts
Patch immediately- CVE-2013-6420 is a high-severity vulnerability (CVSS 7.5 v2) affecting PHP, Mac OS X (Apple), Opensuse and 22 more products.
- It is not listed in any known-exploited vulnerabilities catalog. Public exploit code is available.
- EPSS estimates a 36% probability of exploitation in the next 30 days.
- Fixed versions are available, including apache2-mod_php5 5.6.28-1.1, apache2-mod_php53 5.3.17-0.31.1, apache2-mod_php7 7.0.14-1.4.
- Brandefense priority: patch immediately, because public exploit code exists for a high-severity flaw.
Scores
CVSS v2
7.5
AV:N/AC:L/Au:N/C:P/I:P/A:P
EPSS (30-day exploit likelihood)
36%
Higher than 98.4% of all scored CVEs
Exploit maturity
Proof of concept
ATLAS score
42/100
Publication score, see How it works
Exploitation Verdict
KEV listed
Not listed
Federal due date
None
No federal due date
Ransomware use
Not reported
Attributed actors
None named
Exploit & Defence Guidance
Exploit maturity
Proof of concept
Public exploit code
1
Proof-of-concept links
In-the-wild evidence
1
Reports of active use
Advisories And Exploit References
- advisoryRHSA-2013:1813
- advisoryRHSA-2013:1814
- advisoryRHSA-2013:1815
- advisoryRHSA-2013:1824
- advisoryRHSA-2013:1825
- advisoryRHSA-2013:1826
Description
The asn1_time_to_time_t function in ext/openssl/openssl.c in PHP before 5.3.28, 5.4.x before 5.4.23, and 5.5.x before 5.5.7 does not properly parse (1) notBefore and (2) notAfter timestamps in X.509 certificates, which allows remote attackers to execute arbitrary code or cause a denial of service (memory corruption) via a crafted certificate that is not properly handled by the openssl_x509_parse function.
Affected Products
569 affected entries in total| Product | Affected versions | Fixed in |
|---|---|---|
| PHPPHP | 5.3.0, 5.3.1, 5.3.10, 5.3.11, 5.3.12, 5.3.13, 5.3.14, 5.3.15 | 5.3.27 |
| Mac OS XApple | See advisory | 10.9.1 |
| OpensuseOpensuse | 11.4, 12.2, 12.3, 13.1 | n/a |
| php5debian | See advisory | 5.3.3-7+squeeze18 |
| php54-bcmathamazon | See advisory | 5.4.23-1.49.amzn1 |
Patched Releases
apache2-mod_php5
5.6.28-1.1
apache2-mod_php53
5.3.17-0.31.1
apache2-mod_php7
7.0.14-1.4
Mac OS X
10.9.1
PHP
0:4.3.2-57.ent, 0:4.3.9-3.37.el4.1, 0:5.1.6-40.el5_9.1, 0:5.3.3-3.el6_2.11, 5.1.6-43.el5_10, 5.3.28-1.2.amzn1, 5.3.3-27.el6_5, 5.3.27
php-bcmath
5.1.6-43.el5_10, 5.3.28-1.2.amzn1, 5.3.3-27.el6_5
php-cli
5.1.6-43.el5_10, 5.3.28-1.2.amzn1, 5.3.3-27.el6_5
php-common
5.1.6-43.el5_10, 5.3.28-1.2.amzn1, 5.3.3-27.el6_5
php-dba
5.1.6-43.el5_10, 5.3.28-1.2.amzn1, 5.3.3-27.el6_5
php-devel
5.1.6-43.el5_10, 5.3.28-1.2.amzn1, 5.3.3-27.el6_5
php-embedded
5.3.28-1.2.amzn1, 5.3.3-27.el6_5
php-enchant
5.3.28-1.2.amzn1, 5.3.3-27.el6_5
php-fpm
5.3.28-1.2.amzn1, 5.3.3-27.el6_5
php-gd
5.1.6-43.el5_10, 5.3.28-1.2.amzn1, 5.3.3-27.el6_5
php-imap
5.1.6-43.el5_10, 5.3.28-1.2.amzn1, 5.3.3-27.el6_5
php-intl
5.3.28-1.2.amzn1, 5.3.3-27.el6_5
php-ldap
5.1.6-43.el5_10, 5.3.28-1.2.amzn1, 5.3.3-27.el6_5
php-mbstring
5.1.6-43.el5_10, 5.3.28-1.2.amzn1, 5.3.3-27.el6_5
php-mcrypt
5.3.28-1.2.amzn1
php-mssql
5.3.28-1.2.amzn1
php-mysql
5.1.6-43.el5_10, 5.3.28-1.2.amzn1, 5.3.3-27.el6_5
php-mysqlnd
5.3.28-1.2.amzn1
php-ncurses
5.1.6-43.el5_10
php-odbc
5.1.6-43.el5_10, 5.3.28-1.2.amzn1, 5.3.3-27.el6_5
php-pdo
5.1.6-43.el5_10, 5.3.28-1.2.amzn1, 5.3.3-27.el6_5
Timeline
Publicly disclosed
Dec 10, 2013
Last updated
Mar 9, 2026
Weakness Type
- CWE-119 Improper Restriction of Operations within the Bounds of a Memory Buffer
- CWE-130 Improper Handling of Length Parameter Inconsistency
- CWE-131 Incorrect Calculation of Buffer Size
References
- advisoryRHSA-2013:1813
- advisoryRHSA-2013:1814
- advisoryRHSA-2013:1815
- advisoryRHSA-2013:1824
- advisoryRHSA-2013:1825
FAQ
Common Questions.
The asn1_time_to_time_t function in ext/openssl/openssl.c in PHP before 5.3.28, 5.4.x before 5.4.23, and 5.5.x before 5.5.7 does not properly parse (1) notBefore and (2) notAfter timestamps in X.509 certificates, which allows remote attackers to execute arbitrary code or cause a denial of service (memory corruption) v…
Affected: PHP versions 5.3.0, 5.3.1, 5.3.10, 5.3.11, 5.3.12, 5.3.13, 5.3.14, 5.3.15; Mac OS X (Apple); Opensuse versions 11.4, 12.2, 12.3, 13.1, among others. The full list is in the CVE brief.
It is not listed in any known-exploited vulnerabilities catalog.
No, it is not currently listed in the CISA Known Exploited Vulnerabilities catalog.
Public exploit code is available.
Fixed versions are available, including apache2-mod_php5 5.6.28-1.1, apache2-mod_php53 5.3.17-0.31.1, apache2-mod_php7 7.0.14-1.4.
Brandefense priority: patch immediately, because public exploit code exists for a high-severity flaw.
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