ISC BIND up to 9.17.1 TSIG tsig.c Message assertion

CVSS Meta Temp Score
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CTI Interest Score
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6.1$0-$5k0.00

A vulnerability classified as problematic was found in ISC BIND up to 9.17.1 (Domain Name Software). This vulnerability affects an unknown code block of the file tsig.c of the component TSIG Handler. The manipulation as part of a Message leads to a assertion vulnerability. The CWE definition for the vulnerability is CWE-617. The product contains an assert() or similar statement that can be triggered by an attacker, which leads to an application exit or other behavior that is more severe than necessary. As an impact it is known to affect availability. CVE summarizes:

Using a specially-crafted message, an attacker may potentially cause a BIND server to reach an inconsistent state if the attacker knows (or successfully guesses) the name of a TSIG key used by the server. Since BIND, by default, configures a local session key even on servers whose configuration does not otherwise make use of it, almost all current BIND servers are vulnerable. In releases of BIND dating from March 2018 and after, an assertion check in tsig.c detects this inconsistent state and deliberately exits. Prior to the introduction of the check the server would continue operating in an inconsistent state, with potentially harmful results.

The weakness was published 05/19/2020 (oss-sec). The advisory is shared for download at openwall.com. This vulnerability was named CVE-2020-8617 since 02/05/2020. The attack needs to be approached locally. No form of authentication is required for a successful exploitation. There are known technical details, but no exploit is available. The advisory points out:

An error in BIND code which checks the validity of messages containing TSIG resource records can be exploited by an attacker to trigger an assertion failure in tsig.c, resulting in denial of service to clients.

Upgrading to version 9.11.19, 9.14.12 or 9.16.3 eliminates this vulnerability.

Similar entry is available at 155439.

Productinfo

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Vendor

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Version

License

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB CVSS-B Score: 🔍
VulDB CVSS-BT Score: 🔍
VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

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

VulDB Base Score: 4.0
VulDB Temp Score: 3.8
VulDB Vector: 🔍
VulDB Reliability: 🔍

Vendor Base Score (ISC): 7.5
Vendor Vector (ISC): 🔍

NVD Base Score: 7.5
NVD Vector: 🔍

CVSSv2info

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

Exploitinginfo

Class: Assertion
CWE: CWE-617
ATT&CK: Unknown

Local: Yes
Remote: No

Availability: 🔍
Status: Not defined

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

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Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔍

Upgrade: BIND 9.11.19/9.14.12/9.16.3

Timelineinfo

02/05/2020 🔍
05/19/2020 +104 days 🔍
05/20/2020 +1 days 🔍
10/18/2020 +151 days 🔍

Sourcesinfo

Vendor: isc.org

Advisory: openwall.com
Status: Not defined
Confirmation: 🔍

CVE: CVE-2020-8617 (🔍)
See also: 🔍

Entryinfo

Created: 05/20/2020 06:31
Updated: 10/18/2020 19:21
Changes: 05/20/2020 06:31 (54), 05/20/2020 06:36 (12), 10/18/2020 19:21 (1)
Complete: 🔍

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