CVE-2019-7303: Snapd seccomp filter TIOCSTI ioctl bypass

Severity: high (CVSS 7.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 3.7% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2019-04-23 · updated 2026-06-17
Weakness: CWE-628

Description

A vulnerability in the seccomp filters of Canonical snapd before version 2.37.4 allows a strict mode snap to insert characters into a terminal on a 64-bit host. The seccomp rules were generated to match 64-bit ioctl(2) commands on a 64-bit platform; however, the Linux kernel only uses the lower 32 bits to determine which ioctl(2) commands to run. This issue affects: Canonical snapd versions prior to 2.37.4.

Affected products

Canonical Ltd. snapd: before 2.37.4 — fixed in 2.37.4
Canonical Ubuntu Linux: 14.04, 16.04, 18.04, 18.10

How to fix

Upgrade to a fixed version: Canonical Ltd. snapd 2.37.4. Check the vendor advisory for mitigations.

References

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