Description
The line printer daemon (lpd) in the lpr package in multiple Linux operating systems authenticates by comparing the reverse-resolved hostname of the local machine to the hostname of the print server as returned by gethostname, which allows remote attackers to bypass intended access controls by modifying the DNS for the attacking IP.
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 14 | lpr | 1:0.48-1 | — |
| Debian 13 | lpr | 1:0.48-1 | — |
| Debian 12 | lpr | 1:0.48-1 | — |
Public exploits
Exploit or proof-of-concept code for this vulnerability is publicly available, which lowers the bar for attackers. Treat it as a reason to patch sooner.
Exploit-DB 1
- RedHat 6.1 / IRIX 6.5.18 - 'lpd' Command Execution EDB-19722 · remote · Jan 11, 2000 · verified
Sources: PoC-in-GitHub, Metasploit Framework, Exploit-DB — updated daily. Only links are listed; no exploit code is hosted here.
References
- 20000109 lpr -- access control problem and root exploit vendor-advisory
- A010800-v vendor-advisory
- 927 vdb-entry
- RHSA-2000:002 vendor-advisory
- VU#30308 third-party-advisory
- 20000108 Quadruple Inverted Backflip vendor-advisory
- redhat-lpd-auth(3840) vdb-entry