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.").

The Unity Linux 20 host has a package installed that is affected by a vulnerability as referenced in the UTSA-2025-989100 advisory.

    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.).

Tenable has extracted the preceding description block directly from the Unity Linux security advisory.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

The Unity Linux 20 host has a package installed that is affected by a vulnerability as referenced in the UTSA-2025-986717 advisory.

    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.).

Tenable has extracted the preceding description block directly from the Unity Linux security advisory.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.

  - 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.).
    (CVE-2021-47244)

Note that Nessus relies on the presence of the package as reported by the vendor.

ID	Name	Product	Family	Severity
273117	Unity Linux 20.1070a Security Update: kernel (UTSA-2025-989100)	Nessus	Unity Linux Local Security Checks	medium
267978	Unity Linux 20.1070e Security Update: kernel (UTSA-2025-986717)	Nessus	Unity Linux Local Security Checks	medium
253780	Linux Distros Unpatched Vulnerability : CVE-2021-47244	Nessus	Misc.	medium

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CVE-2021-47244

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medium