Linux Kernel up to 5.3.9 Flow Dissector flow_dissector.c hashmd Track information disclosure

Summaryinfo

A vulnerability was found in Linux Kernel up to 5.3.9. It has been rated as problematic. The impacted element is an unknown function of the file net/core/flow_dissector.c of the component Flow Dissector. Performing a manipulation of the argument hashmd as part of IPv6 Packet results in information disclosure (Track). This vulnerability is cataloged as CVE-2019-18282. It is possible to initiate the attack remotely. There is no exploit available. It is recommended to apply a patch to fix this issue.

Detailsinfo

A vulnerability, which was classified as problematic, was found in Linux Kernel up to 5.3.9 (Operating System). This affects an unknown function of the file net/core/flow_dissector.c of the component Flow Dissector. The manipulation of the argument hashmd as part of a IPv6 Packet leads to a information disclosure vulnerability (Track). CWE is classifying the issue as CWE-200. The product exposes sensitive information to an actor that is not explicitly authorized to have access to that information. This is going to have an impact on confidentiality. The summary by CVE is:

The flow_dissector feature in the Linux kernel 4.3 through 5.x before 5.3.10 has a device tracking vulnerability, aka CID-55667441c84f. This occurs because the auto flowlabel of a UDP IPv6 packet relies on a 32-bit hashmd value as a secret, and because jhash (instead of siphash) is used. The hashmd value remains the same starting from boot time, and can be inferred by an attacker. This affects net/core/flow_dissector.c and related code.

The weakness was shared 01/16/2020 as confirmed git commit (GIT Repository). It is possible to read the advisory at git.kernel.org. This vulnerability is uniquely identified as CVE-2019-18282 since 10/23/2019. The exploitability is told to be easy. 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 attack technique deployed by this issue is T1592 according to MITRE ATT&CK.

Upgrading to version 5.3.10 eliminates this vulnerability. Applying a patch is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be patching the affected component.

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Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 5.3.0
• 5.3.1
• 5.3.2
• 5.3.3
• 5.3.4
• 5.3.5
• 5.3.6
• 5.3.7
• 5.3.8
• 5.3.9

License

• open-source

Website

• Vendor: https://www.kernel.org/

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