CVE-2021-47152: linux kernel Memory Corruption — Fix

Description

In the Linux kernel, the following vulnerability has been resolved: mptcp: fix data stream corruption Maxim reported several issues when forcing a TCP transparent proxy to use the MPTCP protocol for the inbound connections. He also provided a clean reproducer. The problem boils down to 'mptcp_frag_can_collapse_to()' assuming that only MPTCP will use the given page_frag. If others - e.g. the plain TCP protocol - allocate page fragments, we can end-up re-using already allocated memory for mptcp_data_frag. Fix the issue ensuring that the to-be-expanded data fragment is located at the current page frag end. v1 -> v2: - added missing fixes tag (Mat)

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CVSS v3.1 Score

5.5

MEDIUM

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Weakness Type (CWE)

CWE-787 Out-of-bounds Write

Affected Products

Vendor	Product	Versions
linux	linux_kernel	5.7 — 5.10.42
linux	linux_kernel	5.11 — 5.12.9
linux	linux_kernel	All
linux	linux_kernel	All
linux	linux_kernel	All

References

Advisories & Patches

https://git.kernel.org/stable/c/18e7f0580da15cac1e79d73683ada5a9e70980f8 https://git.kernel.org/stable/c/29249eac5225429b898f278230a6ca2baa1ae154 https://git.kernel.org/stable/c/3267a061096efc91eda52c2a0c61ba76e46e4b34 https://git.kernel.org/stable/c/18e7f0580da15cac1e79d73683ada5a9e70980f8 https://git.kernel.org/stable/c/29249eac5225429b898f278230a6ca2baa1ae154 https://git.kernel.org/stable/c/3267a061096efc91eda52c2a0c61ba76e46e4b34

Frequently Asked Questions

What is CVE-2021-47152? +

In the Linux kernel, the following vulnerability has been resolved: mptcp: fix data stream corruption Maxim reported several issues when forcing a TCP transparent proxy to use the MPTCP protocol for the inbound connections. He also provided a clean reproducer. The problem boils down to 'mptcp_frag_can_collapse_to()' assuming that only MPTCP will use the given page_frag. If others - e.g. the plain TCP protocol - allocate page fragments, we can end-up re-using already allocated memory for mptcp_data_frag. Fix the issue ensuring that the to-be-expanded data fragment is located at the current page frag end. v1 -> v2: - added missing fixes tag (Mat) It has a CVSS v3.1 base score of 5.5 (MEDIUM).

How severe is CVE-2021-47152? +

CVE-2021-47152 has a CVSS v3.1 score of 5.5 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance.

What products are affected by CVE-2021-47152? +

CVE-2021-47152 affects products from linux, specifically: linux_kernel. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2021-47152? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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