CVE-2018-3871: An exploitable out-of-bounds write exists in the PCX parsing functionality of Canvas Draw version 4.0.0

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HIGH 7.8DOWNGRADE

CVE-2018-3871 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 PCX parsing functionality of Canvas Draw version 4.0.0. A specially crafted PCX 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. A different vulnerability than CVE-2018-3870.

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	1.5% (top 26%)
CISA exploited list	No
Weakness	CWE-787
Published	2018-07-19
Last modified	2026-06-17

Publisher (CNA): Talos · Vendor: acdsystems

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

Am I affected?

Timeline

2018-07-19 19:29 UTCPublished CVE record published
2026-06-17 01:57 UTCUpdated Record last modified

acdsystems canvas draw DOWNGRADE

Affected: 4.0.0

Fixed in: no fixed release known

Safe to downgrade to: a release before 4.0.0

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 4.0.0 (Debian / Ubuntu)

apt-cache madison canvas-draw sudo apt install canvas-draw=<VERSION_BEFORE_4.0.0> 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_4.0.0> 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-2018-3871?

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

Is CVE-2018-3871 being exploited?

CVE-2018-3871 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-2018-3871 affect?

CVE-2018-3871 affects canvas draw. Severity is high (CVSS 7.8). An exploitable out-of-bounds write exists in the PCX parsing functionality of Canvas Draw version 4.0.0. A specially crafted PCX image processed via the application can lead to an out-of-bounds write, overwriting arbitrary data. An attacker

How urgent is CVE-2018-3871?

Priority 51/100. 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-2018-3973 HIGH 7.8 DOWNGRADE An exploitable out of bounds write exists in the CAL parsing functionality of Canvas Draw version 5.0.0
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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