CVE-2003-1020: The format_send_to_gui function in formats.c for irssi before 0.8.9 allows remote IRC users to cause a denial

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MEDIUM 5.0WATCHLISTDOWNGRADEMITIGATE

CVE-2003-1020 is a medium-severity flaw (CVSS 5.0) affecting irssi, mandrake linux. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

The format_send_to_gui function in formats.c for irssi before 0.8.9 allows remote IRC users to cause a denial of service (crash).

Why this priority

On your watchlist

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

Risk facts

CVSS score	5.0 (Medium)
EPSS exploit chance	1.4% (top 28%)
CISA exploited list	No
Published	2004-01-05
Last modified	2026-06-16

Publisher (CNA): MITRE · Vendor: irssi · mandrakesoft

Last updated 2026-06-16 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2004-01-05 05:00 UTCPublished CVE record published
2026-06-16 22:03 UTCUpdated Record last modified

irssi irssi DOWNGRADE

Affected: 0.8.4 · 0.8.5 · 0.8.6 · 0.8.7 · 0.8.8

Fixed in: no fixed release known

Safe to downgrade to: a release before 0.8.4

1. Check installed version

apt-cache policy irssi || rpm -q irssi || irssi --version

2. No fixed release: DOWNGRADE to a release before 0.8.4 (Debian / Ubuntu)

apt-cache madison irssi sudo apt install irssi=<VERSION_BEFORE_0.8.4> sudo apt-mark hold irssi

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

dnf --showduplicates list irssi sudo dnf downgrade irssi-<VERSION_BEFORE_0.8.4> sudo dnf versionlock add irssi

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.

mandrakesoft mandrake linux MITIGATE

Affected: 9.1 · 9.2

Fixed in: no fixed release known

Safe to downgrade to: a release before 9.1

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-2003-1020?

irssi: downgrade or apply the listed mitigation; mandrake linux: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2003-1020 being exploited?

CVE-2003-1020 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-2003-1020 affect?

CVE-2003-1020 affects irssi, mandrake linux. Severity is medium (CVSS 5.0). The format_send_to_gui function in formats.c for irssi before 0.8.9 allows remote IRC users to cause a denial of service (crash).

How urgent is CVE-2003-1020?

Priority 41/100. On your watchlist

Related CVEs

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CVE-2019-15717 CRITICAL 9.8 UPGRADE MITIGATE Irssi 1.2.x before 1.2.2 has a use-after-free if the IRC server sends a double CAP.
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References

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