Adminer 5.5.1 through 6.0.1 improperly parses the login 'server' string in the host_port() function…

Why it is Yellow

• CVSS 5.8 medium
• On your watchlist: php

References

• https://github.com/vrana/adminer/security/advisories/GHSA-rwxg-xph9-82cj
• https://www.vulncheck.com/advisories/adminer-before-6.0.2-privileged-port-ssrf-via-host-port-regex
• https://github.com/vrana/adminer/security/advisories/GHSA-rwxg-xph9-82cj

Original description

Adminer 5.5.1 through 6.0.1 improperly parses the login 'server' string in the host_port() function in adminer/include/functions.inc.php. The port capture group requires pure digits anchored to the end of the string, so any server value with a non-digit tail fails the regex and falls back to returning the whole string as the host with an empty port. Because the privileged-port restriction in adminer/include/auth.inc.php inspects only the parsed port, the check is skipped, and the mysqli/mysqlnd client subsequently re-parses host:port from the host string and opens a TCP connection. A remote, unauthenticated attacker who can reach the Adminer login page can submit a crafted value such as 127.0.0.1:80/x to make the server initiate TCP connections to arbitrary internal hosts and privileged ports before credentials are validated, enabling server-side request forgery and blind internal port scanning (connection refused vs. handshake vs. timeout acts as a liveness oracle). This is a regression that re-opens the bypass fixed in 5.5.0 (GHSA-58cq-mgw2-38m5). Fixed in 6.0.2.