Description
phpBB 2.0.21 does not properly handle pathnames ending in %00, which allows remote authenticated administrative users to upload arbitrary files, as demonstrated by a query to admin/admin_board.php with an avatar_path parameter ending in .php%00.
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 4.0 | phpbb2 | 2.0.21-7 | DSA-1488-1 |
| Debian 3.1 | phpbb2 | 2.0.13+1-6sarge4 | DSA-1488-1 |
Advisories 1
- DSA-1488-1 phpbb2 - several vulnerabilities Debian Security (DSA / DLA) · Mar 9, 2026
References
- 20347 vdb-entry
- 20060911 ShAnKaR: multiple PHP application poison NULL byte vulnerability mailing-list
- http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=388120
- 28871 third-party-advisory
- phpbb-nullbyte-file-upload(28884) vdb-entry
- 21806 vdb-entry
- DSA-1488 vendor-advisory
- http://www.security.nnov.ru/Odocument221.html
- http://www.phpbb.com/phpBB/viewtopic.php?f=14&t=489624
- 22188 third-party-advisory