CVE-2013-6420

Exp

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.

Published: 2013-12-17 Last update: 2026-04-29 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2013-6420 is rated High Exploit Risk (84/100): CVSS High severity, with high exploitation likelihood (EPSS 40.22%, 97th percentile). 2 public exploit reference(s) are indexed (Exploit-DB). EPSS rose +5.30% over the last day, indicating growing attacker interest. Public exploits are available—assess exposure, apply mitigations, and prioritize patching.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Public exploit references (Exploit-DB) for CVE-2013-6420

EDB-ID Source Kind Published Link
30395 exploit_db edb 2013-12-17 Exploit-DB ↗
— nvd_ref exploit_tag Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2013-6420

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-03-04 34.92% 40.22% +5.30%
2 2026-03-01 40.22% 34.92% -5.30%
3 2026-02-18 — 40.22% —

Full EPSS history (40 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2013-6420

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.5 2.0 HIGH
AV:N/AC:L/Au:N/C:P/I:P/A:P Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:P)
Partial integrity impact.
Availability impact (A:P)
Partial availability impact.
 10.0 6.4 [email protected]

Weakness enumeration for CVE-2013-6420

OS Trackers for CVE-2013-6420

vendor priority summary link
gentoo high CVE-2013-6420: 1 GLSA(s) (201408-11), 1 atom(s) (dev-lang/php); latest impact high. https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2013-6420
redhat critical — https://access.redhat.com/security/cve/CVE-2013-6420
suse high CVE-2013-6420 severity important: SUSE including 648 source package names (apache2-mod_php5-5.2.14-0.7.30.50.1, apache2-mod_php5-5.2.14-0.7.30.54.1, …), 1266 product×package rows across 31 product lines (SUSE Enterprise Storage 7.1, SUSE Linux Enterprise High Performance Computing 15 SP3-ESPOS, … (31 product lines)): Fixed 763, Known Not Affected 503. https://www.suse.com/security/cve/CVE-2013-6420/
ubuntu medium CVE-2013-6420 medium priority: Ubuntu including 1 source packages (php5), 6 status rows across 6 suites (lucid, precise, quantal, raring, saucy, upstream): released 5, needs-triage 1. https://ubuntu.com/security/CVE-2013-6420

Affected software / configurations for CVE-2013-6420

Vendor Product Version Raw CPE
php php 5.4.0 cpe:2.3:a:php:php:5.4.0:*:*:*:*:*:*:*
php php 5.4.1 cpe:2.3:a:php:php:5.4.1:*:*:*:*:*:*:*
php php 5.4.2 cpe:2.3:a:php:php:5.4.2:*:*:*:*:*:*:*
php php 5.4.3 cpe:2.3:a:php:php:5.4.3:*:*:*:*:*:*:*
php php 5.4.4 cpe:2.3:a:php:php:5.4.4:*:*:*:*:*:*:*
php php 5.4.5 cpe:2.3:a:php:php:5.4.5:*:*:*:*:*:*:*
php php 5.4.6 cpe:2.3:a:php:php:5.4.6:*:*:*:*:*:*:*
php php 5.4.7 cpe:2.3:a:php:php:5.4.7:*:*:*:*:*:*:*
php php 5.4.8 cpe:2.3:a:php:php:5.4.8:*:*:*:*:*:*:*
php php 5.4.9 cpe:2.3:a:php:php:5.4.9:*:*:*:*:*:*:*
php php 5.4.10 cpe:2.3:a:php:php:5.4.10:*:*:*:*:*:*:*
php php 5.4.11 cpe:2.3:a:php:php:5.4.11:*:*:*:*:*:*:*
php php 5.4.12 cpe:2.3:a:php:php:5.4.12:*:*:*:*:*:*:*
php php 5.4.12 cpe:2.3:a:php:php:5.4.12:rc1:*:*:*:*:*:*
php php 5.4.12 cpe:2.3:a:php:php:5.4.12:rc2:*:*:*:*:*:*
php php 5.4.13 cpe:2.3:a:php:php:5.4.13:*:*:*:*:*:*:*
php php 5.4.13 cpe:2.3:a:php:php:5.4.13:rc1:*:*:*:*:*:*
php php 5.4.14 cpe:2.3:a:php:php:5.4.14:*:*:*:*:*:*:*
php php 5.4.14 cpe:2.3:a:php:php:5.4.14:rc1:*:*:*:*:*:*
php php 5.4.15 cpe:2.3:a:php:php:5.4.15:*:*:*:*:*:*:*
php php 5.4.15 cpe:2.3:a:php:php:5.4.15:rc1:*:*:*:*:*:*
php php 5.4.16 cpe:2.3:a:php:php:5.4.16:*:*:*:*:*:*:*
php php 5.4.16 cpe:2.3:a:php:php:5.4.16:rc1:*:*:*:*:*:*
php php 5.4.17 cpe:2.3:a:php:php:5.4.17:*:*:*:*:*:*:*
php php 5.4.18 cpe:2.3:a:php:php:5.4.18:*:*:*:*:*:*:*
php php 5.4.19 cpe:2.3:a:php:php:5.4.19:*:*:*:*:*:*:*
php php 5.4.20 cpe:2.3:a:php:php:5.4.20:*:*:*:*:*:*:*
php php 5.4.21 cpe:2.3:a:php:php:5.4.21:*:*:*:*:*:*:*
php php 5.4.22 cpe:2.3:a:php:php:5.4.22:*:*:*:*:*:*:*
opensuse opensuse 11.4 cpe:2.3:o:opensuse:opensuse:11.4:*:*:*:*:*:*:*
opensuse opensuse 12.2 cpe:2.3:o:opensuse:opensuse:12.2:*:*:*:*:*:*:*
opensuse opensuse 12.3 cpe:2.3:o:opensuse:opensuse:12.3:*:*:*:*:*:*:*
opensuse opensuse 13.1 cpe:2.3:o:opensuse:opensuse:13.1:*:*:*:*:*:*:*
apple mac_os_x <= 10.9.1 cpe:2.3:o:apple:mac_os_x:*:*:*:*:*:*:*:*
php php <= 5.3.27 cpe:2.3:a:php:php:*:*:*:*:*:*:*:*
php php 5.3.0 cpe:2.3:a:php:php:5.3.0:*:*:*:*:*:*:*
php php 5.3.1 cpe:2.3:a:php:php:5.3.1:*:*:*:*:*:*:*
php php 5.3.2 cpe:2.3:a:php:php:5.3.2:*:*:*:*:*:*:*
php php 5.3.3 cpe:2.3:a:php:php:5.3.3:*:*:*:*:*:*:*
php php 5.3.4 cpe:2.3:a:php:php:5.3.4:*:*:*:*:*:*:*
php php 5.3.5 cpe:2.3:a:php:php:5.3.5:*:*:*:*:*:*:*
php php 5.3.6 cpe:2.3:a:php:php:5.3.6:*:*:*:*:*:*:*
php php 5.3.7 cpe:2.3:a:php:php:5.3.7:*:*:*:*:*:*:*
php php 5.3.8 cpe:2.3:a:php:php:5.3.8:*:*:*:*:*:*:*
php php 5.3.9 cpe:2.3:a:php:php:5.3.9:*:*:*:*:*:*:*
php php 5.3.10 cpe:2.3:a:php:php:5.3.10:*:*:*:*:*:*:*
php php 5.3.11 cpe:2.3:a:php:php:5.3.11:*:*:*:*:*:*:*
php php 5.3.12 cpe:2.3:a:php:php:5.3.12:*:*:*:*:*:*:*
php php 5.3.13 cpe:2.3:a:php:php:5.3.13:*:*:*:*:*:*:*
php php 5.3.14 cpe:2.3:a:php:php:5.3.14:*:*:*:*:*:*:*
php php 5.3.15 cpe:2.3:a:php:php:5.3.15:*:*:*:*:*:*:*
php php 5.3.16 cpe:2.3:a:php:php:5.3.16:*:*:*:*:*:*:*
php php 5.3.17 cpe:2.3:a:php:php:5.3.17:*:*:*:*:*:*:*
php php 5.3.18 cpe:2.3:a:php:php:5.3.18:*:*:*:*:*:*:*
php php 5.3.19 cpe:2.3:a:php:php:5.3.19:*:*:*:*:*:*:*
php php 5.3.20 cpe:2.3:a:php:php:5.3.20:*:*:*:*:*:*:*
php php 5.3.21 cpe:2.3:a:php:php:5.3.21:*:*:*:*:*:*:*
php php 5.3.22 cpe:2.3:a:php:php:5.3.22:*:*:*:*:*:*:*
php php 5.3.23 cpe:2.3:a:php:php:5.3.23:*:*:*:*:*:*:*
php php 5.3.24 cpe:2.3:a:php:php:5.3.24:*:*:*:*:*:*:*
php php 5.3.25 cpe:2.3:a:php:php:5.3.25:*:*:*:*:*:*:*
php php 5.3.26 cpe:2.3:a:php:php:5.3.26:*:*:*:*:*:*:*
php php 5.5.0 cpe:2.3:a:php:php:5.5.0:*:*:*:*:*:*:*
php php 5.5.0 cpe:2.3:a:php:php:5.5.0:alpha1:*:*:*:*:*:*
php php 5.5.0 cpe:2.3:a:php:php:5.5.0:alpha2:*:*:*:*:*:*
php php 5.5.0 cpe:2.3:a:php:php:5.5.0:alpha3:*:*:*:*:*:*
php php 5.5.0 cpe:2.3:a:php:php:5.5.0:alpha4:*:*:*:*:*:*
php php 5.5.0 cpe:2.3:a:php:php:5.5.0:alpha5:*:*:*:*:*:*
php php 5.5.0 cpe:2.3:a:php:php:5.5.0:alpha6:*:*:*:*:*:*
php php 5.5.0 cpe:2.3:a:php:php:5.5.0:beta1:*:*:*:*:*:*
php php 5.5.0 cpe:2.3:a:php:php:5.5.0:beta2:*:*:*:*:*:*
php php 5.5.0 cpe:2.3:a:php:php:5.5.0:beta3:*:*:*:*:*:*
php php 5.5.0 cpe:2.3:a:php:php:5.5.0:beta4:*:*:*:*:*:*
php php 5.5.0 cpe:2.3:a:php:php:5.5.0:rc1:*:*:*:*:*:*
php php 5.5.0 cpe:2.3:a:php:php:5.5.0:rc2:*:*:*:*:*:*
php php 5.5.1 cpe:2.3:a:php:php:5.5.1:*:*:*:*:*:*:*
php php 5.5.2 cpe:2.3:a:php:php:5.5.2:*:*:*:*:*:*:*
php php 5.5.3 cpe:2.3:a:php:php:5.5.3:*:*:*:*:*:*:*
php php 5.5.4 cpe:2.3:a:php:php:5.5.4:*:*:*:*:*:*:*
php php 5.5.5 cpe:2.3:a:php:php:5.5.5:*:*:*:*:*:*:*

References for CVE-2013-6420

URL Tags
http://forums.interworx.com/threads/8000-InterWorx-Version-5-0-14-Released-on-Beta-Channel%21
http://git.php.net/?p=php-src.git%3Ba=commit%3Bh=c1224573c773b6845e83505f717fbf820fc18415
http://lists.opensuse.org/opensuse-updates/2013-12/msg00125.html
http://lists.opensuse.org/opensuse-updates/2013-12/msg00126.html
http://rhn.redhat.com/errata/RHSA-2013-1813.html
http://rhn.redhat.com/errata/RHSA-2013-1815.html
http://rhn.redhat.com/errata/RHSA-2013-1824.html
http://rhn.redhat.com/errata/RHSA-2013-1825.html
http://rhn.redhat.com/errata/RHSA-2013-1826.html
http://secunia.com/advisories/59652
http://support.apple.com/kb/HT6150
http://www.debian.org/security/2013/dsa-2816
http://www.php.net/ChangeLog-5.php
http://www.securityfocus.com/bid/64225
http://www.securitytracker.com/id/1029472
http://www.ubuntu.com/usn/USN-2055-1
https://bugzilla.redhat.com/show_bug.cgi?id=1036830 Patch
https://h20564.www2.hp.com/hpsc/doc/public/display?docId=emr_na-c04463322
https://www.sektioneins.de/advisories/advisory-012013-php-openssl_x509_parse-memory-corruption-vulnerability.html Exploit
cvelogic Threat Intelligence