CVE-2019-6978 Use after free in n/a

Critical 9.8 Published 28 Jan 2019 Updated 4 Aug 2024

A double free vulnerability in LibGD allows attackers to cause denial of service or potentially execute arbitrary code via crafted image files.

Exploited in the wild: Not known
Login needed: Not needed
Attackable: Over the internet
Victim action needed: Not needed
Fix: Available

What is CVE-2019-6978?

CVE-2019-6978 is a critical use after free vulnerability in Canonical Ubuntu Linux, published on 28 Jan 2019. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

The GD Graphics Library (aka LibGD) 2.2.5 has a double free in the gdImage*Ptr() functions in gd_gif_out.c, gd_jpeg.c, and gd_wbmp.c. NOTE: PHP is unaffected.

Weakness: CWE-415

Which versions are affected by CVE-2019-6978?

It affects 3 products.

Linux distribution packages (29)

`libwmf` AlmaLinux:8	All versions	`0.2.9-8.el8_0`
`libwmf-devel` AlmaLinux:8	All versions	`0.2.9-8.el8_0`
`libwmf-lite` AlmaLinux:8	All versions	`0.2.9-8.el8_0`
`libwmf` Red Hat:enterprise_linux:7::client	All versions	`0:0.2.8.4-44.el7`
`libwmf-debuginfo` Red Hat:enterprise_linux:7::client	All versions	`0:0.2.8.4-44.el7`
`libwmf-devel` Red Hat:enterprise_linux:7::client	All versions	`0:0.2.8.4-44.el7`
`libwmf-lite` Red Hat:enterprise_linux:7::client	All versions	`0:0.2.8.4-44.el7`
`libwmf` Red Hat:enterprise_linux:7::computenode	All versions	`0:0.2.8.4-44.el7`
`libwmf-debuginfo` Red Hat:enterprise_linux:7::computenode	All versions	`0:0.2.8.4-44.el7`
`libwmf-devel` Red Hat:enterprise_linux:7::computenode	All versions	`0:0.2.8.4-44.el7`
`libwmf-lite` Red Hat:enterprise_linux:7::computenode	All versions	`0:0.2.8.4-44.el7`
`libwmf` Red Hat:enterprise_linux:7::server	All versions	`0:0.2.8.4-44.el7`
`libwmf-debuginfo` Red Hat:enterprise_linux:7::server	All versions	`0:0.2.8.4-44.el7`
`libwmf-devel` Red Hat:enterprise_linux:7::server	All versions	`0:0.2.8.4-44.el7`
`libwmf-lite` Red Hat:enterprise_linux:7::server	All versions	`0:0.2.8.4-44.el7`
`libwmf` Red Hat:enterprise_linux:7::workstation	All versions	`0:0.2.8.4-44.el7`
`libwmf-debuginfo` Red Hat:enterprise_linux:7::workstation	All versions	`0:0.2.8.4-44.el7`
`libwmf-devel` Red Hat:enterprise_linux:7::workstation	All versions	`0:0.2.8.4-44.el7`
`libwmf-lite` Red Hat:enterprise_linux:7::workstation	All versions	`0:0.2.8.4-44.el7`
`libwmf` Red Hat:enterprise_linux:8::appstream	All versions	`0:0.2.9-8.el8_0`
`libwmf-debuginfo` Red Hat:enterprise_linux:8::appstream	All versions	`0:0.2.9-8.el8_0`
`libwmf-debugsource` Red Hat:enterprise_linux:8::appstream	All versions	`0:0.2.9-8.el8_0`
`libwmf-lite` Red Hat:enterprise_linux:8::appstream	All versions	`0:0.2.9-8.el8_0`
`libwmf-lite-debuginfo` Red Hat:enterprise_linux:8::appstream	All versions	`0:0.2.9-8.el8_0`
`libwmf-debuginfo` Red Hat:enterprise_linux:8::crb	All versions	`0:0.2.9-8.el8_0`
`libwmf-debugsource` Red Hat:enterprise_linux:8::crb	All versions	`0:0.2.9-8.el8_0`
`libwmf-devel` Red Hat:enterprise_linux:8::crb	All versions	`0:0.2.9-8.el8_0`
`libwmf-lite-debuginfo` Red Hat:enterprise_linux:8::crb	All versions	`0:0.2.9-8.el8_0`
`libwmf` Rocky Linux:8	All versions	`0:0.2.9-8.el8_0`

Products include Canonical Ubuntu Linux, Debian Debian Linux, Libgd Libgd.

How do I fix CVE-2019-6978?

Apply the vendor's patch.

Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.

Is CVE-2019-6978 being exploited?

There is no known exploitation of CVE-2019-6978 in the wild and no public exploit code.

All Canonical Ubuntu Linux vulnerabilities

Sources

Also known as ALPINE-CVE-2019-6978, ALSA-2019:2722, CVE-2018-15878, CVE-2018-15879, DEBIAN-CVE-2019-6978, GHSA-7v6r-3q36-qvvp and 5 more.