MIT Kerberos process_tgs_req() denial of service

kerberos-processtgsreq-dos (71655) The risk level is classified as MediumMedium Risk


MIT Kerberos is vulnerable to a denial of service, caused by a NULL pointer dereference in the process_tgs_req() function. By sending a specially-crafted TGS request, a remote attacker could exploit this vulnerability to cause the KDC daemon to crash.


Base Score: 6.8
  Access Vector: Network
  Access Complexity: Low
  Authentication: Single
  Confidentiality Impact: None
  Integrity Impact: None
  Availability Impact: Complete
Temporal Score: 5.9
  Exploitability: High
  Remediation Level: Official-Fix
  Report Confidence: Confirmed


Denial of Service


Refer to MITKRB5-SA-2011-007 for patch, upgrade or suggested workaround information. See References.


  • MITKRB5-SA-2011-007: KDC null pointer dereference in TGS handling.
  • BID-50929: MIT Kerberos KDC TGS Handling NULL Pointer Dereference Denial Of Service Vulnerability
  • CVE-2011-1530: The process_tgs_req function in do_tgs_req.c in the Key Distribution Center (KDC) in MIT Kerberos 5 (aka krb5) 1.9 through 1.9.2 allows remote authenticated users to cause a denial of service (NULL pointer dereference and daemon crash) via a crafted TGS request that triggers an error other than the KRB5_KDB_NOENTRY error.
  • OSVDB ID: 77572: MIT Kerberos 5 src/kdc/do_tgs_req.c process_tgs_req() Function TGS Request Parsing Remote DoS
  • RHSA-2011-1790: Moderate: krb5 security update
  • SA47124: Kerberos KDC "process_tgs_req()" NULL Pointer Dereference Denial of Service Vulnerability

Platforms Affected:

  • MIT Kerberos 5
  • MIT Kerberos 5 1.0
  • MIT Kerberos 5 1.0.6
  • MIT Kerberos 5 1.1
  • MIT Kerberos 5 1.1.1
  • MIT Kerberos 5 1.2 Beta1
  • MIT Kerberos 5 1.2 Beta2
  • MIT Kerberos 5 1.3.3
  • MIT Kerberos 5-1.3
  • MIT Kerberos 5-1.4
  • MIT Kerberos 5-1.5
  • MIT Kerberos 5-1.6
  • MIT Kerberos 5-1.7
  • MIT Kerberos 5-1.8
  • MIT Kerberos 5-1.8.4
  • MIT Kerberos 5-1.9
  • RedHat Enterprise Linux 6 Workstation
  • RedHat Enterprise Linux 6 Server
  • RedHat Enterprise Linux Desktop 6
  • RedHat Enterprise Linux HPC Node 6


Dec 06, 2011

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