Vulnerability Description
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, when running PHP FPM SAPI with main FPM daemon process running as root and child worker processes running as lower-privileged users, it is possible for the child processes to access memory shared with the main process and write to it, modifying it in a way that would cause the root process to conduct invalid memory reads and writes, which can be used to escalate privileges from local unprivileged user to the root user.
CVSS Score
HIGH
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Php | Php | >= 7.3.0, <= 7.3.31 |
| Debian | Debian Linux | 9.0 |
| Fedoraproject | Fedora | 33 |
| Netapp | Clustered Data Ontap | - |
| Oracle | Communications Diameter Signaling Router | >= 8.0.0.0, <= 8.5.0.2 |
Related Weaknesses (CWE)
References
- http://www.openwall.com/lists/oss-security/2021/10/26/7Mailing ListPatchThird Party Advisory
- https://bugs.php.net/bug.php?id=81026ExploitIssue TrackingPatch
- https://lists.debian.org/debian-lts-announce/2021/10/msg00021.htmlMailing ListThird Party Advisory
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedorapro
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedorapro
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedorapro
- https://security.gentoo.org/glsa/202209-20Third Party Advisory
- https://security.netapp.com/advisory/ntap-20211118-0003/Third Party Advisory
- https://www.debian.org/security/2021/dsa-4992Third Party Advisory
- https://www.debian.org/security/2021/dsa-4993Third Party Advisory
- https://www.oracle.com/security-alerts/cpuapr2022.htmlPatchVendor Advisory
- https://www.oracle.com/security-alerts/cpujan2022.htmlPatchVendor Advisory
- http://www.openwall.com/lists/oss-security/2021/10/26/7Mailing ListPatchThird Party Advisory
- https://bugs.php.net/bug.php?id=81026ExploitIssue TrackingPatch
- https://lists.debian.org/debian-lts-announce/2021/10/msg00021.htmlMailing ListThird Party Advisory
FAQ
What is CVE-2021-21703?
CVE-2021-21703 is a vulnerability with a CVSS score of 7.8 (HIGH). 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, when running PHP FPM SAPI with main FPM daemon process running as root and child worker processes running a...
How severe is CVE-2021-21703?
CVE-2021-21703 has been rated HIGH with a CVSS base score of 7.8/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2021-21703?
Check the references section above for vendor advisories and patch information. Affected products include: Php Php, Debian Debian Linux, Fedoraproject Fedora, Netapp Clustered Data Ontap, Oracle Communications Diameter Signaling Router.