CVE-2021-21703

Summary

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.

Affected Software

VendorProductVersion RangeStatus
PHP GroupPHP7.3.x <= 7.3.31affected
PHP GroupPHP7.4.x < 7.4.25affected
PHP GroupPHP8.0.X < 8.0.12affected

Weaknesses

  • CWE-787: CWE-787 Out-of-bounds Write
  • CWE-284: CWE-284 Improper Access Control

ADP Enrichment

CVE Program Container

Additional References

References