CVE-2021-47245

HIGH
Published May 21, 2024 Modified Dec 30, 2024 CWE-125

Description

In the Linux kernel, the following vulnerability has been resolved: netfilter: synproxy: Fix out of bounds when parsing TCP options The TCP option parser in synproxy (synproxy_parse_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."). v2 changes: Added an early return when length < 0 to avoid calling skb_header_pointer with negative length.

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CVSS v3.1 Score

7.1
HIGH
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H

Weakness Type (CWE)

CWE-125 Out-of-bounds Read

Affected Products

Vendor Product
linux linux_kernel
linux linux_kernel
linux linux_kernel
linux linux_kernel
linux linux_kernel
linux linux_kernel
linux linux_kernel
linux linux_kernel
linux linux_kernel
linux linux_kernel
linux linux_kernel
linux linux_kernel
linux linux_kernel

References

Advisories & Patches

https://git.kernel.org/stable/c/576c1526b4d83c44ad7b673cb841f36cbc6cb6c4 https://git.kernel.org/stable/c/5fc177ab759418c9537433e63301096e733fb915 https://git.kernel.org/stable/c/674b5f0c6a4fc5d3abce877048290cea6091fcb1 https://git.kernel.org/stable/c/6defc77d48eff74075b80ad5925061b2fc010d98 https://git.kernel.org/stable/c/7d9a9a1a88a3da574e019b4de756bc73337b3b0b https://git.kernel.org/stable/c/9cdf299ba4e153b5e56187648420de22c6216f02 https://git.kernel.org/stable/c/e1eb98cfeafdd85537e7e3cefe93ca9bfbcc3ea8 https://git.kernel.org/stable/c/f648089337cb8ed40b2bb96e244f72b9d97dc96b https://git.kernel.org/stable/c/576c1526b4d83c44ad7b673cb841f36cbc6cb6c4 https://git.kernel.org/stable/c/5fc177ab759418c9537433e63301096e733fb915 https://git.kernel.org/stable/c/674b5f0c6a4fc5d3abce877048290cea6091fcb1 https://git.kernel.org/stable/c/6defc77d48eff74075b80ad5925061b2fc010d98 https://git.kernel.org/stable/c/7d9a9a1a88a3da574e019b4de756bc73337b3b0b https://git.kernel.org/stable/c/9cdf299ba4e153b5e56187648420de22c6216f02 https://git.kernel.org/stable/c/e1eb98cfeafdd85537e7e3cefe93ca9bfbcc3ea8 https://git.kernel.org/stable/c/f648089337cb8ed40b2bb96e244f72b9d97dc96b

Frequently Asked Questions

What is CVE-2021-47245? +
In the Linux kernel, the following vulnerability has been resolved: netfilter: synproxy: Fix out of bounds when parsing TCP options The TCP option parser in synproxy (synproxy_parse_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."). v2 changes: Added an early return when length < 0 to avoid calling skb_header_pointer with negative length. It has a CVSS v3.1 base score of 7.1 (HIGH).
How severe is CVE-2021-47245? +
CVE-2021-47245 has a CVSS v3.1 score of 7.1 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching.
What products are affected by CVE-2021-47245? +
CVE-2021-47245 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-2021-47245? +
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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