Description
rad_decode in FreeRADIUS 0.9.2 and earlier allows remote attackers to cause a denial of service (crash) via a short RADIUS string attribute with a tag, which causes memcpy to be called with a -1 length argument, as demonstrated using the Tunnel-Password attribute.
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 | freeradius | 0.9.2-4 | — |
| Debian 13 | freeradius | 0.9.2-4 | — |
| Debian 12 | freeradius | 0.9.2-4 | — |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 3 | freeradius | 0.9.3-1 | RHSA-2003:386 |
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.
Third-party code, not reviewed by us. Public PoCs are sometimes fake or contain malware. Read the code first and run it only in an isolated lab, against systems you are authorised to test.
Exploit-DB 1
- FreeRadius 0.x/1.1.x - Tag Field Heap Corruption EDB-23391 · dos · Nov 20, 2003 · verified
Sources: PoC-in-GitHub, Metasploit Framework, Exploit-DB — updated daily. Only links are listed; no exploit code is hosted here.
Advisories 1
- RHSA-2003:386 Red Hat Security Advisory: freeradius security update Red Hat Security Advisories (RHSA) · Jun 26, 2026
References
- 20031120 Remote DoS in FreeRADIUS, all versions. mailing-list
- http://marc.info/?l=freeradius-users&m=106947389449613&w=2
- RHSA-2003:386 vendor-advisory
- oval:org.mitre.oval:def:10917 vdb-entry signature
- 20031121 FreeRADIUS 0.9.2 "Tunnel-Password" attribute Handling Vulnerability mailing-list