NULL pointer dereference in Zsh

CVE-2018-7548

In subst.c in zsh through 5.4.2, there is a NULL pointer dereference when using ${(PA)...} on an empty array result.

EPSS: 0.026 (83.7th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

Affected products

Zsh
Canonical Ubuntu_linux — versions 17.10
N/a — versions n/a

Weakness classification (CWE)

CWE-476 — NULL Pointer Dereference

References

cve@mitre.org (x_refsource_UBUNTU, vendor-advisory, Third Party Advisory)
cve@mitre.org (vendor-advisory, Third Party Advisory, x_refsource_GENTOO)
cve@mitre.org (Patch, Third Party Advisory, x_refsource_MISC)

Frequently asked questions

What is CVE-2018-7548?: CVE-2018-7548 is a critical-severity vulnerability in Zsh, classified under NULL Pointer Dereference. CVSS score: 9.8/10. Published 2018-02-27.
How severe is CVE-2018-7548?: Critical severity. CVSS v3 base score is 9.8 out of 10.