CVE-2016-3120

krb5: S4U2Self KDC crash when anon is restricted

Severity Score

6.5

*CVSS v3

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

*Multiple Sources

Exploited in Wild

*KEV

Decision

*SSVC

Descriptions

The validate_as_request function in kdc_util.c in the Key Distribution Center (KDC) in MIT Kerberos 5 (aka krb5) before 1.13.6 and 1.4.x before 1.14.3, when restrict_anonymous_to_tgt is enabled, uses an incorrect client data structure, which allows remote authenticated users to cause a denial of service (NULL pointer dereference and daemon crash) via an S4U2Self request.

La función validate_as_request en kdc_util.c en el Key Distribution Center (KDC) en MIT Kerberos 5 (también conocido como krb5) en versiones anteriores a 1.13.6 y 1.4.x en versiones anteriores a 1.14.3, cuando restrict_anonymous_to_tgt está activo, utiliza una estructura de datos de clientes incorrecta, lo que permite a usuarios remotos autenticados provocar una denegación de servicio (referencia al puntero NULO y caída de daemon) a través de una petición S4U2Selft.

A NULL pointer dereference flaw was found in MIT Kerberos krb5kdc service. An authenticated attacker could use this flaw to cause krb5kdc to dereference a null pointer and crash by making an S4U2Self request, if the restrict_anonymous_to_tgt option was set to true.

*Credits: N/A

CVSS Scores

Attack Vector

Network

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

None

Availability

High

Attack Vector

Network

Attack Complexity

High

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

None

Availability

High

Attack Vector

Network

Attack Complexity

Low

Authentication

Single

Confidentiality

None

Integrity

None

Availability

Partial

Attack Vector

Network

Attack Complexity

Medium

Authentication

Single

Confidentiality

None

Integrity

None

Availability

Partial

* Common Vulnerability Scoring System

SSVC

Decision:-

Exploitation

Automatable

Tech. Impact

* Organization's Worst-case Scenario

Timeline

2016-03-11 CVE Reserved
2016-08-01 CVE Published
2023-11-01 EPSS Updated
2024-08-05 CVE Updated
---------- Exploited in Wild
---------- KEV Due Date
---------- First Exploit

CWE

CWE-476: NULL Pointer Dereference

CAPEC

References (12)

URL	Tag	Source
http://krbdev.mit.edu/rt/Ticket/Display.html?id=8458	Issue Tracking
http://web.mit.edu/kerberos/krb5-1.13	X_refsource_confirm
http://web.mit.edu/kerberos/krb5-1.14	X_refsource_confirm
http://www.securityfocus.com/bid/92132	Vdb Entry
http://www.securitytracker.com/id/1036442	Vdb Entry
https://github.com/krb5/krb5/commit/93b4a6306a0026cf1cc31ac4bd8a49ba5d034ba7	X_refsource_confirm
https://lists.debian.org/debian-lts-announce/2018/01/msg00040.html	Mailing List

URL	Date	SRC

URL	Date	SRC

URL	Date	SRC
http://lists.opensuse.org/opensuse-updates/2016-09/msg00035.html	2023-11-07
http://rhn.redhat.com/errata/RHSA-2016-2591.html	2023-11-07
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/AWL3KYFRJIX37EAM4DKCQQIQP2WBKL35	2023-11-07
https://access.redhat.com/security/cve/CVE-2016-3120	2016-11-03
https://bugzilla.redhat.com/show_bug.cgi?id=1361050	2016-11-03

Affected Vendors, Products, and Versions

Vendor		Product				Version		Other		Status
Vendor	Product	Version	Other	Status	<-- -->	Vendor	Product	Version	Other	Status
Mit Search vendor "Mit"		Kerberos 5 Search vendor "Mit" for product "Kerberos 5"				1.13 Search vendor "Mit" for product "Kerberos 5" and version "1.13"		-		Affected
Mit Search vendor "Mit"		Kerberos 5 Search vendor "Mit" for product "Kerberos 5"				1.13.1 Search vendor "Mit" for product "Kerberos 5" and version "1.13.1"		-		Affected
Mit Search vendor "Mit"		Kerberos 5 Search vendor "Mit" for product "Kerberos 5"				1.13.2 Search vendor "Mit" for product "Kerberos 5" and version "1.13.2"		-		Affected
Mit Search vendor "Mit"		Kerberos 5 Search vendor "Mit" for product "Kerberos 5"				1.13.3 Search vendor "Mit" for product "Kerberos 5" and version "1.13.3"		-		Affected
Mit Search vendor "Mit"		Kerberos 5 Search vendor "Mit" for product "Kerberos 5"				1.13.4 Search vendor "Mit" for product "Kerberos 5" and version "1.13.4"		-		Affected
Mit Search vendor "Mit"		Kerberos 5 Search vendor "Mit" for product "Kerberos 5"				1.13.5 Search vendor "Mit" for product "Kerberos 5" and version "1.13.5"		-		Affected
Mit Search vendor "Mit"		Kerberos 5 Search vendor "Mit" for product "Kerberos 5"				1.13.6 Search vendor "Mit" for product "Kerberos 5" and version "1.13.6"		-		Affected
Mit Search vendor "Mit"		Kerberos 5 Search vendor "Mit" for product "Kerberos 5"				1.14 Search vendor "Mit" for product "Kerberos 5" and version "1.14"		-		Affected
Mit Search vendor "Mit"		Kerberos 5 Search vendor "Mit" for product "Kerberos 5"				1.14.1 Search vendor "Mit" for product "Kerberos 5" and version "1.14.1"		-		Affected
Mit Search vendor "Mit"		Kerberos 5 Search vendor "Mit" for product "Kerberos 5"				1.14.2 Search vendor "Mit" for product "Kerberos 5" and version "1.14.2"		-		Affected