CVE-2005-2040: Multiple buffer overflows in the getterminaltype function in telnetd for Heimdal before 0.6.5 may allow remote

Routine

MEDIUM 5.0DOWNGRADE

CVE-2005-2040 is a medium-severity flaw (CVSS 5.0) affecting telnetd. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Multiple buffer overflows in the getterminaltype function in telnetd for Heimdal before 0.6.5 may allow remote attackers to execute arbitrary code, a different vulnerability than CVE-2005-0468 and CVE-2005-0469.

Why this priority

No elevated risk signals yet

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

Risk facts

CVSS score	5.0 (Medium)
EPSS exploit chance	2.8% (top 13%)
CISA exploited list	No
Published	2005-06-20
Last modified	2026-06-16

Publisher (CNA): MITRE · Vendor: telnetd

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

Am I affected?

Timeline

2005-06-20 04:00 UTCPublished CVE record published
2026-06-16 22:14 UTCUpdated Record last modified

telnetd telnetd DOWNGRADE

Affected: 0.3f · 0.4a · 0.4b · 0.4c · 0.4d · 0.4e · 0.5.0 · 0.5.1

Fixed in: no fixed release known

Safe to downgrade to: a release before 0.3f

1. Check installed version

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

2. No fixed release: DOWNGRADE to a release before 0.3f (Debian / Ubuntu)

apt-cache madison telnetd sudo apt install telnetd=<VERSION_BEFORE_0.3f> sudo apt-mark hold telnetd

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

dnf --showduplicates list telnetd sudo dnf downgrade telnetd-<VERSION_BEFORE_0.3f> sudo dnf versionlock add telnetd

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-2005-2040?

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

Is CVE-2005-2040 being exploited?

CVE-2005-2040 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-2005-2040 affect?

CVE-2005-2040 affects telnetd. Severity is medium (CVSS 5.0). Multiple buffer overflows in the getterminaltype function in telnetd for Heimdal before 0.6.5 may allow remote attackers to execute arbitrary code, a different vulnerability than CVE-2005-0468 and CVE-2005-0469.

How urgent is CVE-2005-2040?

Priority 39/100. No elevated risk signals yet.

Related CVEs

CVE-2004-0998 HIGH 7.5 DOWNGRADE DOWNGRADE Format string vulnerability in telnetd-ssl 0.17 and earlier allows remote attackers to execute arbitrary code.

References

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