ISC BIND up to 9.15.0 dispatch.c Malformed Packet race condition

Summaryinfo

A vulnerability was found in ISC BIND up to 9.15.0. It has been classified as problematic. This impacts an unknown function of the file dispatch.c. Performing a manipulation as part of Malformed Packet results in race condition. This vulnerability is known as CVE-2019-6471. Remote exploitation of the attack is possible. No exploit is available.

Detailsinfo

A vulnerability was found in ISC BIND up to 9.15.0 (Domain Name Software). It has been classified as problematic. This affects an unknown code block of the file dispatch.c. The manipulation as part of a Malformed Packet leads to a race condition vulnerability. CWE is classifying the issue as CWE-362. The product contains a code sequence that can run concurrently with other code, and the code sequence requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence that is operating concurrently. This is going to have an impact on availability. The summary by CVE is:

A race condition which may occur when discarding malformed packets can result in BIND exiting due to a REQUIRE assertion failure in dispatch.c. Versions affected: BIND 9.11.0 -> 9.11.7, 9.12.0 -> 9.12.4-P1, 9.14.0 -> 9.14.2. Also all releases of the BIND 9.13 development branch and version 9.15.0 of the BIND 9.15 development branch and BIND Supported Preview Edition versions 9.11.3-S1 -> 9.11.7-S1.

The weakness was published 10/09/2019 (Website). It is possible to read the advisory at kb.isc.org. This vulnerability is uniquely identified as CVE-2019-6471 since 01/16/2019. It is possible to initiate the attack remotely. No form of authentication is needed for exploitation. Technical details of the vulnerability are known, but there is no available exploit. The pricing for an exploit might be around USD $0-$5k at the moment (estimation calculated on 05/21/2025).

The vulnerability scanner Nessus provides a plugin with the ID 236577 (Alibaba Cloud Linux 3 : 0025: bind (ALINUX3-SA-2021:0025)), which helps to determine the existence of the flaw in a target environment.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

The vulnerability is also documented in the vulnerability database at Tenable (236577). Similar entries are available at VDB-143294, VDB-143293, VDB-143292 and VDB-143291. Be aware that VulDB is the high quality source for vulnerability data.

Productinfo

Type

• Domain Name Software

Vendor

• ISC

Name

• BIND

Version

• 9.11.7
• 9.11.7-S1
• 9.12.4-P1
• 9.13.0
• 9.14.2
• 9.15.0

License

• open-source

Website

• Vendor: https://www.isc.org/

CPE 2.3info

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Entryinfo

Be aware that VulDB is the high quality source for vulnerability data.

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