Vulnerability Details : CVE-2015-8994
An issue was discovered in PHP 5.x and 7.x, when the configuration uses apache2handler/mod_php or php-fpm with OpCache enabled. With 5.x after 5.6.28 or 7.x after 7.0.13, the issue is resolved in a non-default configuration with the opcache.validate_permission=1 setting. The vulnerability details are as follows. In PHP SAPIs where PHP interpreters share a common parent process, Zend OpCache creates a shared memory object owned by the common parent during initialization. Child PHP processes inherit the SHM descriptor, using it to cache and retrieve compiled script bytecode ("opcode" in PHP jargon). Cache keys vary depending on configuration, but filename is a central key component, and compiled opcode can generally be run if a script's filename is known or can be guessed. Many common shared-hosting configurations change EUID in child processes to enforce privilege separation among hosted users (for example using mod_ruid2 for the Apache HTTP Server, or php-fpm user settings). In these scenarios, the default Zend OpCache behavior defeats script file permissions by sharing a single SHM cache among all child PHP processes. PHP scripts often contain sensitive information: Think of CMS configurations where reading or running another user's script usually means gaining privileges to the CMS database.
Threat overview for CVE-2015-8994
Top countries where our scanners detected CVE-2015-8994
Top open port discovered on systems with this issue
80
IPs affected by CVE-2015-8994 605,829
Threat actors abusing to this issue?
Yes
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Exploit prediction scoring system (EPSS) score for CVE-2015-8994
Probability of exploitation activity in the next 30 days: 0.45%
Percentile, the proportion of vulnerabilities that are scored at or less: ~ 72 % EPSS Score History EPSS FAQ
CVSS scores for CVE-2015-8994
Base Score | Base Severity | CVSS Vector | Exploitability Score | Impact Score | Score Source |
---|---|---|---|---|---|
6.8
|
MEDIUM | AV:N/AC:M/Au:N/C:P/I:P/A:P |
8.6
|
6.4
|
NIST |
7.5
|
HIGH | CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H |
1.6
|
5.9
|
NIST |
CWE ids for CVE-2015-8994
-
Assigned by: nvd@nist.gov (Primary)
References for CVE-2015-8994
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https://ma.ttias.be/a-better-way-to-run-php-fpm/
A better way to run PHP-FPMExploit;Technical Description;Third Party Advisory
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http://marc.info/?l=php-internals&m=147876797317925&w=2
'[PHP-DEV] Re: [PATCH] opcache bug #69090, prepend user identifier to keys' - MARCMailing List
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https://bugs.php.net/bug.php?id=69090
PHP :: Request #69090 :: add prefix/xor to cache keys/check permissions or separate cachesExploit;Issue Tracking
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http://seclists.org/oss-sec/2017/q1/520
oss-sec: CVE Request: PHP with Zend OPCache code permission/sensitive data protection vulnerabilityMailing List;Third Party Advisory
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http://seclists.org/oss-sec/2016/q4/343
oss-sec: CVE Request: PHP with Zend OPCache code permission/sensitive data protection vulnerabilitiesMailing List;Third Party Advisory
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http://openwall.com/lists/oss-security/2017/02/28/1
oss-security - Re: CVE Request: PHP with Zend OPCache code permission/sensitive data protection vulnerabilityMailing List
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http://marc.info/?l=php-internals&m=147921016724565&w=2
'[PHP-DEV] Re: [PATCH] opcache bug #69090, prepend user identifier to keys' - MARCMailing List
Products affected by CVE-2015-8994
- cpe:2.3:a:php:php:*:*:*:*:*:*:*:*
- cpe:2.3:a:php:php:*:*:*:*:*:*:*:*