CVE-2006-4021: The cryptographic module in ScatterChat 1.0.x allows attackers to identify patterns in large numbers of messag

Routine

LOW 2.6DOWNGRADE

CVE-2006-4021 is a low-severity flaw (CVSS 2.6) affecting scatterchat. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

The cryptographic module in ScatterChat 1.0.x allows attackers to identify patterns in large numbers of messages by identifying collisions using a birthday attack on the custom padding mechanism for ECB mode encryption.

Why this priority

No elevated risk signals yet

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

Risk facts

CVSS score	2.6 (Low)
EPSS exploit chance	0.7% (top 48%)
CISA exploited list	No
Published	2006-08-17
Last modified	2026-06-16

Publisher (CNA): MITRE · Vendor: scatterchat

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

Am I affected?

Timeline

2006-08-17 21:04 UTCPublished CVE record published
2026-06-16 22:28 UTCUpdated Record last modified

scatterchat scatterchat DOWNGRADE

Affected: 1.0.1

Fixed in: no fixed release known

Safe to downgrade to: a release before 1.0.1

1. Check installed version

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

2. No fixed release: DOWNGRADE to a release before 1.0.1 (Debian / Ubuntu)

apt-cache madison scatterchat sudo apt install scatterchat=<VERSION_BEFORE_1.0.1> sudo apt-mark hold scatterchat

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

dnf --showduplicates list scatterchat sudo dnf downgrade scatterchat-<VERSION_BEFORE_1.0.1> sudo dnf versionlock add scatterchat

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-2006-4021?

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

Is CVE-2006-4021 being exploited?

CVE-2006-4021 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-2006-4021 affect?

CVE-2006-4021 affects scatterchat. Severity is low (CVSS 2.6). The cryptographic module in ScatterChat 1.0.x allows attackers to identify patterns in large numbers of messages by identifying collisions using a birthday attack on the custom padding mechanism for ECB mode encryption.

How urgent is CVE-2006-4021?

Priority 22/100. No elevated risk signals yet.

Related CVEs

CVE-2006-4508 MEDIUM 4.0 UPGRADE DOWNGRADE Unspecified vulnerability in (1) Tor 0.1.0.x before 0.1.0.18 and 0.1.1.x before 0.1.1.23, and (2) ScatterChat

References

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