CVE-2003-0850: The TCP reassembly functionality in libnids before 1.18 allows remote attackers to cause "memory corruption" a

This month

HIGH 7.5DOWNGRADEDOWNGRADE

CVE-2003-0850 is a high-severity flaw (CVSS 7.5) affecting dsniff, libnids. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

The TCP reassembly functionality in libnids before 1.18 allows remote attackers to cause "memory corruption" and possibly execute arbitrary code via "overlarge TCP packets."

Why this priority

High severity

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

Risk facts

CVSS score	7.5 (High)
EPSS exploit chance	3.8% (top 10%)
CISA exploited list	No
Published	2003-11-17
Last modified	2026-06-16

Publisher (CNA): MITRE · Vendor: dug song · rafal wojtczuk

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

Am I affected?

Timeline

2003-11-17 05:00 UTCPublished CVE record published
2026-06-16 22:03 UTCUpdated Record last modified

dug song dsniff DOWNGRADE

Affected: 2.3

Fixed in: no fixed release known

Safe to downgrade to: a release before 2.3

1. Check installed version

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

2. No fixed release: DOWNGRADE to a release before 2.3 (Debian / Ubuntu)

apt-cache madison dsniff sudo apt install dsniff=<VERSION_BEFORE_2.3> sudo apt-mark hold dsniff

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

dnf --showduplicates list dsniff sudo dnf downgrade dsniff-<VERSION_BEFORE_2.3> sudo dnf versionlock add dsniff

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.

rafal wojtczuk libnids DOWNGRADE

Affected: 1.11 · 1.12 · 1.13 · 1.14 · 1.16 · 1.17

Fixed in: no fixed release known

Safe to downgrade to: a release before 1.11

1. Check installed version

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

2. No fixed release: DOWNGRADE to a release before 1.11 (Debian / Ubuntu)

apt-cache madison libnids sudo apt install libnids=<VERSION_BEFORE_1.11> sudo apt-mark hold libnids

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

dnf --showduplicates list libnids sudo dnf downgrade libnids-<VERSION_BEFORE_1.11> sudo dnf versionlock add libnids

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-2003-0850?

dsniff: downgrade or apply the listed mitigation; libnids: downgrade or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2003-0850 being exploited?

CVE-2003-0850 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-2003-0850 affect?

CVE-2003-0850 affects dsniff, libnids. Severity is high (CVSS 7.5). The TCP reassembly functionality in libnids before 1.18 allows remote attackers to cause "memory corruption" and possibly execute arbitrary code via "overlarge TCP packets."

How urgent is CVE-2003-0850?

Priority 49/100. High severity

Related CVEs

CVE-2002-2049 HIGH 7.5 DOWNGRADE DOWNGRADE configure for Dsniff 2.3, fragroute 1.2, and fragrouter 1.6, when downloaded from monkey.org on May 17, 2002,

References

← Back to latest CVEs