CVE-2021-47244

CVE-2021-47244 is a medium-severity vulnerability in Linux Linux Kernel with a CVSS 3.x base score of 6.2. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-125.

Key facts

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.").

Frequently asked questions

What is CVE-2021-47244?
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.").
How severe is CVE-2021-47244?
CVE-2021-47244 has a CVSS 3.x base score of 6.2, rated medium severity. It is exploitable over local access with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2021-47244 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (19th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-47244?
CVE-2021-47244 primarily affects Linux Linux Kernel. In total, 7 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-47244?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2021-47244 have an EU (EUVD) identifier?
Yes. CVE-2021-47244 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2021-33892.
When was CVE-2021-47244 published?
CVE-2021-47244 was published on 2024-05-21 and last updated on 2026-06-17.

References

Affected products (7)

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