CVE-2021-47086: phonet/pep: refuse to enable an unbound pipe

Severity: medium (CVSS 5.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2024-03-04 · updated 2026-06-17

Description

In the Linux kernel, the following vulnerability has been resolved: phonet/pep: refuse to enable an unbound pipe This ioctl() implicitly assumed that the socket was already bound to a valid local socket name, i.e. Phonet object. If the socket was not bound, two separate problems would occur: 1) We'd send an pipe enablement request with an invalid source object. 2) Later socket calls could BUG on the socket unexpectedly being connected yet not bound to a valid object.

Affected products

Linux kernel: before 4.4.297; from 4.5 before 4.9.295; from 4.10 before 4.14.260; from 4.15 before 4.19.223; from 4.20 before 5.4.169; from 5.5 before 5.10.89 — fixed in 4.14.260, 4.19.223, 4.4.297, 4.9.295, 5.10.89, 5.15.12

How to fix

Upgrade to a fixed version: Linux kernel 4.14.260, 4.19.223, 4.4.297, 4.9.295. Check the vendor advisory for mitigations.

References

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