CVE-2018-3973: An exploitable out of bounds write exists in the CAL parsing functionality of Canvas Draw version 5.0.0

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HIGH 7.8DOWNGRADE

CVE-2018-3973 is a high-severity flaw (CVSS 7.8) affecting canvas draw. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

An exploitable out of bounds write exists in the CAL parsing functionality of Canvas Draw version 5.0.0. A specially crafted CAL image processed via the application can lead to an out of bounds write overwriting arbitrary data. An attacker can deliver a PCX image to trigger this vulnerability and gain code execution.

Why this priority

High severity
Public exploit reference

No fix is published yet: follow the downgrade or mitigation steps.

Risk facts

CVSS score	7.8 (High)
Attack vector	Local
Attack complexity	Low
Privileges needed	None
User interaction	Required
EPSS exploit chance	1.9% (top 20%)
CISA exploited list	No
Weakness	CWE-787
Published	2019-02-06
Last modified	2026-06-17

Publisher (CNA): Talos · Vendor: canvasgfx

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2019-02-06 21:29 UTCPublished CVE record published
2026-06-17 01:58 UTCUpdated Record last modified

canvasgfx canvas draw DOWNGRADE

Affected: 5.0.0

Fixed in: no fixed release known

Safe to downgrade to: a release before 5.0.0

1. Check installed version

apt-cache policy canvas-draw || rpm -q canvas-draw || canvas-draw --version

2. No fixed release: DOWNGRADE to a release before 5.0.0 (Debian / Ubuntu)

apt-cache madison canvas-draw sudo apt install canvas-draw=<VERSION_BEFORE_5.0.0> sudo apt-mark hold canvas-draw

2. No fixed release: DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list canvas-draw sudo dnf downgrade canvas-draw-<VERSION_BEFORE_5.0.0> sudo dnf versionlock add canvas-draw

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2018-3973?

canvas draw: downgrade or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2018-3973 being exploited?

CVE-2018-3973 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2018-3973 affect?

CVE-2018-3973 affects canvas draw. Severity is high (CVSS 7.8). An exploitable out of bounds write exists in the CAL parsing functionality of Canvas Draw version 5.0.0. A specially crafted CAL image processed via the application can lead to an out of bounds write overwriting arbitrary data. An attacker

How urgent is CVE-2018-3973?

Priority 52/100. High severity; Public exploit reference

Related CVEs

CVE-2018-3981 HIGH 7.8 DOWNGRADE An exploitable out-of-bounds write exists in the TIFF-parsing functionality of Canvas Draw version 5.0.0
CVE-2018-3980 HIGH 7.8 DOWNGRADE An exploitable out-of-bounds write exists in the TIFF-parsing functionality of Canvas Draw version 5.0.0
CVE-2018-3976 HIGH 7.8 DOWNGRADE An exploitable out-of-bounds write exists in the CALS Raster file format-parsing functionality of Canvas Draw
CVE-2018-3871 HIGH 7.8 DOWNGRADE An exploitable out-of-bounds write exists in the PCX parsing functionality of Canvas Draw version 4.0.0
CVE-2018-3870 HIGH 7.8 DOWNGRADE An exploitable out-of-bounds write exists in the PCX parsing functionality of Canvas Draw version 4.0.0

References

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