CVE-2000-0557: Buffer overflow in the web interface for Cmail 2.4.7 allows remote attackers to execute arbitrary commands via

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HIGH 10.0DOWNGRADE

CVE-2000-0557 is a high-severity flaw (CVSS 10.0) affecting cmail. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Buffer overflow in the web interface for Cmail 2.4.7 allows remote attackers to execute arbitrary commands via a long GET request.

Why this priority

Critical severity
EPSS top 9%: very likely to be exploited
Public exploit reference

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

Risk facts

CVSS score	10.0 (High)
EPSS exploit chance	4.3% (top 9%)
CISA exploited list	No
Published	2000-06-05
Last modified	2026-06-16

Publisher (CNA): MITRE · Vendor: computalynx

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

Am I affected?

Timeline

2000-06-05 04:00 UTCPublished CVE record published
2026-06-16 21:51 UTCUpdated Record last modified

computalynx cmail DOWNGRADE

Affected: 2.4.7

Fixed in: no fixed release known

Safe to downgrade to: a release before 2.4.7

1. Check installed version

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

2. No fixed release: DOWNGRADE to a release before 2.4.7 (Debian / Ubuntu)

apt-cache madison cmail sudo apt install cmail=<VERSION_BEFORE_2.4.7> sudo apt-mark hold cmail

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

dnf --showduplicates list cmail sudo dnf downgrade cmail-<VERSION_BEFORE_2.4.7> sudo dnf versionlock add cmail

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-2000-0557?

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

Is CVE-2000-0557 being exploited?

CVE-2000-0557 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-2000-0557 affect?

CVE-2000-0557 affects cmail. Severity is high (CVSS 10.0). Buffer overflow in the web interface for Cmail 2.4.7 allows remote attackers to execute arbitrary commands via a long GET request.

How urgent is CVE-2000-0557?

Priority 63/100. Critical severity; EPSS top 9%: very likely to be exploited; Public exploit reference

Related CVEs

CVE-2001-0742 HIGH 7.5 DOWNGRADE Buffer overflow in Computalynx CMail POP3 mail server 2.4.9 allows remote attackers to run arbitrary code via
CVE-2000-0556 MEDIUM 5.0 DOWNGRADE Buffer overflow in the web interface for Cmail 2.4.7 allows remote attackers to cause a denial of service by s

References

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