Out-of-bounds Read in Linux

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.

Vulnerability class: Buffer Overflow

Published · last modified .

CVSS v3 metric

CVSS v3 base score 8.2 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:H.

EPSS exploit prediction

EPSS: 0.008 (54.6th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 55th percentile — 54.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2021-47245: held from 0.008 to 0.008.

EPSS over last 30 days · oldest: 0.008 · newest: 0.008 · change: +0.000

Affected products

  • Linux — versions 48b1de4c110a7afa4b85862f6c75af817db26fad, 3.12, 0
  • Linux Kernel — versions 5.13

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2021-47245?
CVE-2021-47245 is a high-severity vulnerability in Linux, classified under Out-of-bounds Read. CVSS score: 8.2/10. Published 2024-05-21.
How severe is CVE-2021-47245?
High severity. CVSS v3 base score is 8.2 out of 10.