Linux Kernel up to 5.7.11 RNG drivers/char/random.c information disclosure

Summaryinfo

A vulnerability marked as problematic has been reported in Linux Kernel up to 5.7.11. Impacted is an unknown function of the file drivers/char/random.c of the component RNG. Performing a manipulation results in information disclosure. This vulnerability is cataloged as CVE-2020-16166. It is possible to initiate the attack remotely. There is no exploit available. To fix this issue, it is recommended to deploy a patch.

Detailsinfo

A vulnerability classified as problematic has been found in Linux Kernel up to 5.7.11 (Operating System). This affects an unknown code of the file drivers/char/random.c of the component RNG. The manipulation with an unknown input leads to a information disclosure vulnerability. 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 Linux kernel through 5.7.11 allows remote attackers to make observations that help to obtain sensitive information about the internal state of the network RNG, aka CID-f227e3ec3b5c. This is related to drivers/char/random.c and kernel/time/timer.c.

The weakness was shared 07/30/2020 as confirmed git commit (GIT Repository). It is possible to read the advisory at git.kernel.org. This vulnerability is uniquely identified as CVE-2020-16166 since 07/30/2020. The exploitability is told to be difficult. 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. The advisory points out:

This modifies the first 32 bits out of the 128 bits of a random CPU's net_rand_state on interrupt or CPU activity to complicate remote observations that could lead to guessing the network RNG's internal state.

The vulnerability scanner Nessus provides a plugin with the ID 208554 (CentOS 7 : kernel-alt (RHSA-2020:4279)), which helps to determine the existence of the flaw in a target environment.

Applying a patch is able to eliminate this problem. The bugfix is ready for download at git.kernel.org.

The vulnerability is also documented in the vulnerability database at Tenable (208554). Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 5.7.0
• 5.7.1
• 5.7.2
• 5.7.3
• 5.7.4
• 5.7.5
• 5.7.6
• 5.7.7
• 5.7.8
• 5.7.9
• 5.7.10
• 5.7.11

License

• open-source

Website

• Vendor: https://www.kernel.org/

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Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

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