MIT Kerberos 5 1.7 KDC Assertion S4U2Self/S4U2Proxy Request input validation

CVSS Meta Temp Score
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CTI Interest Score
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6.3$0-$5k0.00

Summaryinfo

A vulnerability was found in MIT Kerberos 5 1.7. It has been rated as critical. The impacted element is an unknown function of the component KDC Assertion Handler. Performing a manipulation as part of S4U2Self/S4U2Proxy Request results in input validation. This vulnerability is cataloged as CVE-2017-11368. It is possible to initiate the attack remotely. There is no exploit available. Upgrading the affected component is advised.

Detailsinfo

A vulnerability was found in MIT Kerberos 5 1.7 (Network Authentication Software). It has been classified as critical. This affects an unknown function of the component KDC Assertion Handler. The manipulation as part of a S4U2Self/S4U2Proxy Request leads to a input validation vulnerability. CWE is classifying the issue as CWE-20. The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly. This is going to have an impact on availability. The summary by CVE is:

In MIT Kerberos 5 (aka krb5) 1.7 and later, an authenticated attacker can cause a KDC assertion failure by sending invalid S4U2Self or S4U2Proxy requests.

The bug was discovered 07/14/2017. The weakness was shared 08/09/2017 (Website). The advisory is shared at lists.fedoraproject.org. This vulnerability is uniquely identified as CVE-2017-11368 since 07/17/2017. The exploitability is told to be easy. It is possible to initiate the attack remotely. The successful exploitation requires a authentication. Neither technical details nor an exploit are publicly available.

The vulnerability was handled as a non-public zero-day exploit for at least 11 days. During that time the estimated underground price was around $5k-$25k. The vulnerability scanner Nessus provides a plugin with the ID 101997 (Fedora 24 : krb5 (2017-71c47e1e82)), which helps to determine the existence of the flaw in a target environment. It is assigned to the family Fedora Local Security Checks and running in the context l. The commercial vulnerability scanner Qualys is able to test this issue with plugin 157689 (Oracle Enterprise Linux Security Update for krb5 (ELSA-2018-0666)).

Upgrading eliminates this vulnerability. A possible mitigation has been published even before and not after the disclosure of the vulnerability.

The vulnerability is also documented in the databases at Tenable (101997) and SecurityFocus (BID 100291†). The entry VDB-122212 is related to this item. If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Productinfo

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CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 6.5
VulDB Meta Temp Score: 6.3

VulDB Base Score: 6.5
VulDB Temp Score: 6.2
VulDB Vector: 🔍
VulDB Reliability: 🔍

NVD Base Score: 6.5
NVD Vector: 🔍

CVSSv2info

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VulDB Base Score: 🔍
VulDB Temp Score: 🔍
VulDB Reliability: 🔍

NVD Base Score: 🔍

Exploitinginfo

Class: Input validation
CWE: CWE-20
CAPEC: 🔍
ATT&CK: 🔍

Physical: No
Local: No
Remote: Yes

Availability: 🔍
Status: Not defined

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

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Nessus ID: 101997
Nessus Name: Fedora 24 : krb5 (2017-71c47e1e82)
Nessus File: 🔍
Nessus Risk: 🔍
Nessus Family: 🔍
Nessus Context: 🔍

OpenVAS ID: 867773
OpenVAS Name: Fedora Update for krb5 FEDORA-2017-e5b36383f4
OpenVAS File: 🔍
OpenVAS Family: 🔍

Qualys ID: 🔍
Qualys Name: 🔍

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔍

Patch: github.com

Timelineinfo

07/14/2017 🔍
07/17/2017 +3 days 🔍
07/25/2017 +8 days 🔍
07/27/2017 +2 days 🔍
08/09/2017 +13 days 🔍
08/09/2017 +0 days 🔍
08/09/2017 +0 days 🔍
08/10/2017 +1 days 🔍
12/15/2022 +1953 days 🔍

Sourcesinfo

Vendor: mit.edu

Advisory: RHSA-2018:0666
Status: Confirmed
Confirmation: 🔍

CVE: CVE-2017-11368 (🔍)
GCVE (CVE): GCVE-0-2017-11368
GCVE (VulDB): GCVE-100-105189
SecurityFocus: 100291 - MIT Kerberos 5 CVE-2017-11368 Denial of Service Vulnerability

See also: 🔍

Entryinfo

Created: 08/10/2017 08:21
Updated: 12/15/2022 15:23
Changes: 08/10/2017 08:21 (75), 11/06/2019 08:34 (5), 12/15/2022 15:23 (5)
Complete: 🔍
Cache ID: 216::103

If you want to get the best quality for vulnerability data then you always have to consider VulDB.

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