Updated FreeRADIUS packages are now available that fix a denial of service vulnerability.
FreeRADIUS is an Internet authentication daemon, which implements the RADIUS protocol. It allows Network Access Servers (NAS boxes) to perform authentication for dial-up users. The rad_decode function 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. The Common Vulnerabilities and Exposures project (cve.mitre.org) has assigned the name CAN-2003-0967 to this issue. Users of FreeRADIUS are advised to upgrade to these erratum packages containing FreeRADIUS 0.9.3 which is not vulnerable to these issues.