Description
Zeek before 8.0.9 contains a null pointer dereference vulnerability in its Kerberos protocol analyzer that allows unauthenticated remote attackers to crash the sensor by sending a crafted KRB_ERROR message with error-code 25 (KDC_ERR_PREAUTH_REQUIRED) containing a PA-DATA element with padata-type 2, 3, 11, or 19. Attackers can exploit a parser and analyzer state mismatch where proc_padata() dereferences an uninitialized pa_data_element field selected by the wrong parsing arm, triggering a crash via a single UDP or TCP packet to port 88 without any credentials or prior authentication.
Problem types
Product status
Any version before 8.0.9
Credits
Jaime Sánchez Sánchez
References
github.com/zeek/zeek/releases/tag/v8.0.9 (Release Notes)
github.com/...ommit/c82e3c734893d932e94310aec0dbeb1ffcea169d (Patch Commit)
www.vulncheck.com/...ence-dos-via-kerberos-krb-error-parsing