CVE-2021-47244

mptcp: Fix out of bounds when parsing TCP options

HIGH
8.2
CVSS Score
Published: May 21, 2024 at 02:19 PM UTC
Updated: August 5, 2026 at 09:24 AM UTC
1 product affected across 1 vendorLinux Kernel

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Severity
HIGH8.2
Exploit prediction
EPSS 0.7%
SSVC
No known exploit

Description

In the Linux kernel, the following vulnerability has been resolved: mptcp: Fix out of bounds when parsing TCP options The TCP option parser in mptcp (mptcp_get_options) could read one byte out of bounds. When the length is 1, the execution flow gets into the loop, reads one byte of the opcode, and if the opcode is neither TCPOPT_EOL nor TCPOPT_NOP, it reads one more byte, which exceeds the length of 1. This fix is inspired by commit 9609dad263f8 ("ipv4: tcp_input: fix stack out of bounds when parsing TCP options.").

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

5.11 ≤ v < 5.12.135.6 ≤ v < 5.10.465.6 ≤ v < 5.12.135.6 ≤ v < 5.135.13 rc15.13 rc25.13 rc35.13 rc45.13 rc55.13 rc6cec37a6e41aae7bf3df9a3da783380a4d9325fd8
Vendor states this is fixed in 07718be265680dcf496347d475ce1a5442f55ad7 (fixed)
Vendor states this is fixed in 73eeba71dc9932970befa009e68272a3d5ec4a58 (fixed)
Vendor states this is fixed in 76e02b8905d0691e89e104a882f3bba7dd0f6037 (fixed)
Vendor states this is fixed in 5.10.46 (unaffected)
Vendor states this is fixed in 5.12.13 (unaffected)
Vendor states this is fixed in 5.13 (unaffected)
Vendor states this is fixed in 5.6 (unaffected)

References (3)

Patch
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/07718be265680dcf496347d475ce1a5442f55ad7
Patch
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/73eeba71dc9932970befa009e68272a3d5ec4a58
Patch
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/76e02b8905d0691e89e104a882f3bba7dd0f6037

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

8.2HIGHLinux
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-125

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