CVE intelligence and bounded remediation

CVE-2017-18509 — An issue was discovered in net/ipv6/ip6mr.c in the Linux kernel before 4.11

High CVSS 7.8

An issue was discovered in net/ipv6/ip6mr.c in the Linux kernel before 4.11. By setting a specific socket option, an attacker can control a pointer in kernel land and cause an inet_csk_listen_stop general protection fault, or potentially execute arbitrary code under certain circumstances. The issue can be triggered as root (e.g., inside a default LXC container or with the CAP_NET_ADMIN capability) or after namespace unsharing. This occurs because sk_type and protocol are not checked in the appropriate part of the ip6_mroute_* functions. NOTE: this affects Linux distributions that use 4.9.x longterm kernels before 4.9.187.

Severity
High
CVSS
7.8 (3.1)
Published
2019-08-13
CISA KEV
Not currently listed
Ecosystem
linux/kernel
Weaknesses
CWE-20

Affected products

  • linux / linux_kernel
  • canonical / ubuntu_linux / 16.04
  • debian / debian_linux / 8.0
  • debian / debian_linux / 9.0
  • debian / debian_linux / 10.0

Showing 5 representative product identities from 8 source matches. Confirm exact affected versions with the linked vendor and NVD evidence.

Matched remediation archetype

Command, code, expression, and template injection

This catalog composition supplies bounded fallback guidance. Explicitly reviewed curated workflows load with the complete record below.

Check exposure

  • Trace untrusted values to process execution, interpreters, evaluators, template engines, dynamic imports, and administrative scripting features.
  • Determine whether the affected path is reachable across each trust boundary and which service account or host privilege it inherits.
  • Review configuration for optional execution features, unsafe compatibility modes, and shell invocation.

Remediate safely

  • Replace string-built commands or evaluated code with fixed operations and structured argument APIs that do not invoke a shell.
  • Use strict allowlists for operation identifiers and reject unexpected input before it reaches any interpreter.
  • Update the affected component and add inert regression tests covering metacharacters, encoding variants, and alternate request paths.

Authoritative sources

Complete CVE record and remediation plan

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