| Name | CVE-2021-21706 | 
| Description | In PHP versions 7.3.x below 7.3.31, 7.4.x below 7.4.24 and 8.0.x below 8.0.11, in Microsoft Windows environment, ZipArchive::extractTo may be tricked into writing a file outside target directory when extracting a ZIP file, thus potentially causing files to be created or overwritten, subject to OS permissions. | 
| Source | CVE (at NVD; CERT, ENISA, LWN, oss-sec, fulldisc, Debian ELTS, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more) | 
Vulnerable and fixed packages
The table below lists information on source packages.
| Source Package | Release | Version | Status | 
|---|
| php7.4 (PTS) | bullseye | 7.4.33-1+deb11u5 | fixed | 
|  | bullseye (security) | 7.4.33-1+deb11u9 | fixed | 
The information below is based on the following data on fixed versions.
| Package | Type | Release | Fixed Version | Urgency | Origin | Debian Bugs | 
|---|
| php7.0 | source | (unstable) | (not affected) |  |  |  | 
| php7.3 | source | (unstable) | (not affected) |  |  |  | 
| php7.4 | source | (unstable) | (not affected) |  |  |  | 
| php8.0 | source | (unstable) | (not affected) |  |  |  | 
Notes
- php8.0 <not-affected> (Windows specific issue)
- php7.4 <not-affected> (Windows specific issue)
- php7.3 <not-affected> (Windows specific issue)
- php7.0 <not-affected> (Windows specific issue)
Fixed in 8.0.11, 7.4.24, 7.3.31
PHP Bug: https://bugs.php.net/81420