CVE-2020-14983: The server in Chocolate Doom 3.0.0 and Crispy Doom 5.8.0 doesn't validate the user-controlled num_players valu

This week

CRITICAL 9.8REMOTEDOWNGRADEDOWNGRADEMITIGATE

CVE-2020-14983 is a critical-severity flaw (CVSS 9.8) affecting chocolate doom, crispy doom, backports. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

The server in Chocolate Doom 3.0.0 and Crispy Doom 5.8.0 doesn't validate the user-controlled num_players value, leading to a buffer overflow. A malicious user can overwrite the server's stack.

Why this priority

Critical severity
Public exploit reference
Remotely exploitable, no login, no user action

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

Risk facts

CVSS score	9.8 (Critical)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	2.7% (top 14%)
CISA exploited list	No
Weakness	CWE-120
Published	2020-06-22
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: chocolate-doom · opensuse

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

Am I affected?

Timeline

2020-06-22 20:15 UTCPublished CVE record published
2026-06-17 02:55 UTCUpdated Record last modified

chocolate-doom chocolate doom DOWNGRADE

Affected: 3.0.0

Fixed in: no fixed release known

Safe to downgrade to: a release before 3.0.0

1. Check installed version

apt-cache policy chocolate-doom || rpm -q chocolate-doom || chocolate-doom --version

2. No fixed release: DOWNGRADE to a release before 3.0.0 (Debian / Ubuntu)

apt-cache madison chocolate-doom sudo apt install chocolate-doom=<VERSION_BEFORE_3.0.0> sudo apt-mark hold chocolate-doom

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

dnf --showduplicates list chocolate-doom sudo dnf downgrade chocolate-doom-<VERSION_BEFORE_3.0.0> sudo dnf versionlock add chocolate-doom

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.

chocolate-doom crispy doom DOWNGRADE

Affected: 5.8.0

Fixed in: no fixed release known

Safe to downgrade to: a release before 5.8.0

1. Check installed version

apt-cache policy crispy-doom || rpm -q crispy-doom || crispy-doom --version

2. No fixed release: DOWNGRADE to a release before 5.8.0 (Debian / Ubuntu)

apt-cache madison crispy-doom sudo apt install crispy-doom=<VERSION_BEFORE_5.8.0> sudo apt-mark hold crispy-doom

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

dnf --showduplicates list crispy-doom sudo dnf downgrade crispy-doom-<VERSION_BEFORE_5.8.0> sudo dnf versionlock add crispy-doom

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.

opensuse backports MITIGATE

Affected: sle-15 sp1

Fixed in: no fixed release known

Safe to downgrade to: a release before sle-15

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

opensuse leap MITIGATE

Affected: 15.1 · 15.2

Fixed in: no fixed release known

Safe to downgrade to: a release before 15.1

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

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-2020-14983?

chocolate doom: downgrade or apply the listed mitigation; crispy doom: downgrade or apply the listed mitigation; backports: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2020-14983 being exploited?

CVE-2020-14983 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-2020-14983 affect?

CVE-2020-14983 affects chocolate doom, crispy doom, backports. Severity is critical (CVSS 9.8). The server in Chocolate Doom 3.0.0 and Crispy Doom 5.8.0 doesn't validate the user-controlled num_players value, leading to a buffer overflow. A malicious user can overwrite the server's stack.

How urgent is CVE-2020-14983?

Priority 66/100. Critical severity; Public exploit reference; Remotely exploitable, no login, no user action

References

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