CVE-2009-1789: mod/server.mod/servmsg.c in Eggheads Eggdrop and Windrop 1.6.19 and earlier allows remote attackers to cause a

Q: How do I fix CVE-2009-1789?

eggdrop: downgrade or apply the listed mitigation; eggdrop irc bot: upgrade to newer than 1.6.19; windrop: upgrade to newer than 1.6.19. Exact commands for each OS are on this page.

Q: Is CVE-2009-1789 being exploited?

CVE-2009-1789 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2009-1789 affect?

CVE-2009-1789 affects eggdrop, eggdrop irc bot, windrop. Severity is medium (CVSS 4.3). mod/server.mod/servmsg.c in Eggheads Eggdrop and Windrop 1.6.19 and earlier allows remote attackers to cause a denial of service (crash) via a crafted PRIVMSG that causes an empty string to trigger a negative string length copy. NOTE: this

Q: How urgent is CVE-2009-1789?

Priority 44/100. EPSS top 5%: very likely to be exploited; Public exploit reference

This week

MEDIUM 4.3DOWNGRADEUPGRADEUPGRADE

CVE-2009-1789 is a medium-severity flaw (CVSS 4.3) affecting eggdrop, eggdrop irc bot, windrop. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

mod/server.mod/servmsg.c in Eggheads Eggdrop and Windrop 1.6.19 and earlier allows remote attackers to cause a denial of service (crash) via a crafted PRIVMSG that causes an empty string to trigger a negative string length copy. NOTE: this issue exists because of an incorrect fix for CVE-2007-2807.

Why this priority

EPSS top 5%: very likely to be exploited
Public exploit reference

A fixed release or distro patch exists.

Risk facts

CVSS score	4.3 (Medium)
EPSS exploit chance	8.5% (top 5%)
CISA exploited list	No
Published	2009-05-26
Last modified	2026-06-16

Publisher (CNA): MITRE · Vendor: eggheads · philip moore

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

Am I affected?

Timeline

2009-05-26 16:30 UTCPublished CVE record published
2026-06-16 23:08 UTCUpdated Record last modified

eggheads eggdrop DOWNGRADE

Affected: 1.6.0 · 1.6.1 · 1.6.2 · 1.6.3 · 1.6.4 · 1.6.5 · 1.6.6 · 1.6.7

Fixed in: no fixed release known

Safe to downgrade to: a release before 1.6.0

1. Check installed version

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

2. No fixed release: DOWNGRADE to a release before 1.6.0 (Debian / Ubuntu)

apt-cache madison eggdrop sudo apt install eggdrop=<VERSION_BEFORE_1.6.0> sudo apt-mark hold eggdrop

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

dnf --showduplicates list eggdrop sudo dnf downgrade eggdrop-<VERSION_BEFORE_1.6.0> sudo dnf versionlock add eggdrop

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.

eggheads eggdrop irc bot UPGRADE

Affected: <= 1.6.19

Fixed in: newer than 1.6.19

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy eggdrop-irc-bot || rpm -q eggdrop-irc-bot || eggdrop-irc-bot --version

2. UPGRADE to newer than 1.6.19 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade eggdrop-irc-bot

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade eggdrop-irc-bot

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

philip moore windrop UPGRADE

Affected: <= 1.6.19 · 1.4.4 · 1.4.6 · 1.5.4 · 1.5.4 rc1 · 1.5.4 rc2 · 1.5.4a · 1.6.0

Fixed in: newer than 1.6.19

Safe to downgrade to: no unaffected older release

1. Check installed version

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

2. UPGRADE to newer than 1.6.19 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade windrop

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade windrop

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

Public exploits and detection

Public code exists for this CVE. Treat unpatched systems as at risk, and only run PoCs in a lab.

Exploit-DB: Eggdrop/Windrop 1.6.19 - ctcpbuf Remote Crash

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-2009-1789?

eggdrop: downgrade or apply the listed mitigation; eggdrop irc bot: upgrade to newer than 1.6.19; windrop: upgrade to newer than 1.6.19. Exact commands for each OS are on this page.

Is CVE-2009-1789 being exploited?

CVE-2009-1789 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-2009-1789 affect?

CVE-2009-1789 affects eggdrop, eggdrop irc bot, windrop. Severity is medium (CVSS 4.3). mod/server.mod/servmsg.c in Eggheads Eggdrop and Windrop 1.6.19 and earlier allows remote attackers to cause a denial of service (crash) via a crafted PRIVMSG that causes an empty string to trigger a negative string length copy. NOTE: this

How urgent is CVE-2009-1789?

Priority 44/100. EPSS top 5%: very likely to be exploited; Public exploit reference

References

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