CVE-2021-21703: PHP-FPM memory access in root process leading to privilege escalation
First published: Mon Oct 18 2021(Updated: )
Fixed bug (PHP-FPM oob R/W in root process leading to privilege escalation) (CVE-2021-21703).
Credit: security@php.net
| Affected Software | Affected Version | How to fix |
|---|---|---|
| debian/php7.3 | 7.3.31-1~deb10u1 7.3.31-1~deb10u5 | |
| debian/php7.4 | 7.4.33-1+deb11u4 | |
| PHP | <8.0.12 | 8.0.12 |
| PHP | >=7.3.0<=7.3.31 | |
| PHP | >=7.4.0<7.4.25 | |
| PHP | >=8.0.0<8.0.12 | |
| Debian | =9.0 | |
| Debian | =10.0 | |
| Debian | =11.0 | |
| Fedoraproject Fedora | =33 | |
| Fedoraproject Fedora | =34 | |
| Fedoraproject Fedora | =35 | |
| NetApp Clustered Data ONTAP | ||
| Oracle Communications Diameter Signaling Router | >=8.0.0.0<=8.5.0.2 |
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Reference Links
- https://security-tracker.debian.org/tracker/CVE-2021-21703
- https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=997003
- http://bugs.php.net/81026
- https://github.com/php/php-src/commit/fadb1f8c1d08ae62b4f0a16917040fde57a3b93b
- https://www.ambionics.io/blog/php-fpm-local-root
- https://www.openwall.com/lists/oss-security/2021/10/26/7
- http://www.openwall.com/lists/oss-security/2021/10/26/7
- https://bugs.php.net/bug.php?id=81026
- https://lists.debian.org/debian-lts-announce/2021/10/msg00021.html
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/6PZVLICZUJMXOGWOUWSBAEGIVTF6Y6V3/
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/JO5RA6YOBGGGKLIA6F6BQRZDDECF5L3R/
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/PBM3KKB3RY2YPOKNMC4HIH7IH3T3WC74/
- https://security.gentoo.org/glsa/202209-20
- https://security.netapp.com/advisory/ntap-20211118-0003/
- https://www.debian.org/security/2021/dsa-4992
- https://www.debian.org/security/2021/dsa-4993
- https://www.oracle.com/security-alerts/cpuapr2022.html
- https://www.oracle.com/security-alerts/cpujan2022.html
- https://www.php.net/ChangeLog-8.php#8.0.12 (Advisory)
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/JO5RA6YOBGGGKLIA6F6BQRZDDECF5L3R/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/PBM3KKB3RY2YPOKNMC4HIH7IH3T3WC74/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/6PZVLICZUJMXOGWOUWSBAEGIVTF6Y6V3/
Frequently Asked Questions
What is CVE-2021-21703?
CVE-2021-21703 is a vulnerability in PHP versions 7.3.x up to and including 7.3.31, 7.4.x below 7.4.25, and 8.0.x below 8.0.12 that allows child worker processes running as lower-privileged users to access memory shared with the main FPM daemon process running as root, potentially leading to privilege escalation.
What is the severity of CVE-2021-21703?
CVE-2021-21703 has a severity rating of high, with a severity value of 7.
How can I fix CVE-2021-21703?
To fix CVE-2021-21703, you should upgrade to PHP version 8.0.12 or apply the appropriate patches for PHP versions 7.3.x, 7.4.x, and 8.0.x.
Where can I find more information about CVE-2021-21703?
You can find more information about CVE-2021-21703 on the official PHP website and the Openwall mailing list.
What are the CWE identifiers associated with CVE-2021-21703?
CVE-2021-21703 is associated with CWE-787 and CWE-284.
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