{"vuid":"VU#936683","idnumber":"936683","name":"Multiple implementations of the RADIUS protocol do not adequately validate the vendor-length of the vendor-specific attributes","keywords":["Radius Server","FreeRADIUS","Vendor-Specific attribute","Vendor-Length","DoS","denial of service"],"overview":"Various RADIUS servers and clients permit the passing of vendor-specific and user-specific attributes. Several implementations of RADIUS fail to check the Vendor-Length of the Vendor-Specific attribute. It's possible to cause a denial of service against RADIUS servers with a malformed Vendor-Specific attribute.","clean_desc":"RADIUS servers and clients fail to validate the Vendor-Length inside Vendor-Specific attributes. The Vendor-Length shouldn't be less than 2. If Vendor-Length is less than 2, the RADIUS server (or client) calculates the attribute length as a negative number. The attribute length is then used in various functions. In most RADIUS servers the function that performs this calculation is rad_recv() or radrecv(). Some applications may use the same logic to validate user-specific attributes and be vulnerable via the same method. For example, YARDRadius contains this vulnerability in the handling of the User-Specific attributes only.","impact":"It is possible to cause a denial of service against the RADIUS server  with a malformed Vendor-Specific attribute. Though unlikely, if a RADIUS client processes the Vendor-Specific attribute contained in a server response, then the client may also be vulnerable.","resolution":"Apply a patch or upgrade to the version specified by your vendor.","workarounds":"","sysaffected":"","thanks":"Our thanks to 3APA3A <3APA3A@SECURITY.NNOV.RU> for the report and analysis of this vulnerability.","author":"This document was written by Jason Rafail and is based on information provided by 3APA3A.","public":["http://www.freeradius.org","http://online.securityfocus.com/bid/4230"],"cveids":["CVE-2001-1377"],"certadvisory":"CA-2002-06","uscerttechnicalalert":null,"datecreated":"2001-12-14T17:33:57Z","publicdate":"2001-11-29T00:00:00Z","datefirstpublished":"2002-03-04T19:27:06Z","dateupdated":"2002-04-16T18:58:06Z","revision":18,"vrda_d1_directreport":"","vrda_d1_population":"","vrda_d1_impact":"","cam_widelyknown":"5","cam_exploitation":"0","cam_internetinfrastructure":"10","cam_population":"10","cam_impact":"3","cam_easeofexploitation":"14","cam_attackeraccessrequired":"15","cam_scorecurrent":"1.771875","cam_scorecurrentwidelyknown":"3.54375","cam_scorecurrentwidelyknownexploited":"5.90625","ipprotocol":"","cvss_accessvector":"","cvss_accesscomplexity":"","cvss_authentication":null,"cvss_confidentialityimpact":"","cvss_integrityimpact":"","cvss_availabilityimpact":"","cvss_exploitablity":null,"cvss_remediationlevel":"","cvss_reportconfidence":"","cvss_collateraldamagepotential":"","cvss_targetdistribution":"","cvss_securityrequirementscr":"","cvss_securityrequirementsir":"","cvss_securityrequirementsar":"","cvss_basescore":"","cvss_basevector":"","cvss_temporalscore":"","cvss_environmentalscore":"","cvss_environmentalvector":"","metric":1.771875,"vulnote":null}