CVE-2004-0992: Format string vulnerability in the -a option (daemon mode) in Proxytunnel before 1.2.3 allows remote attackers

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HIGH 10.0DOWNGRADE

CVE-2004-0992 is a high-severity flaw (CVSS 10.0) affecting proxytunnel. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Format string vulnerability in the -a option (daemon mode) in Proxytunnel before 1.2.3 allows remote attackers to execute arbitrary code via format string specifiers in an invalid proxy answer.

Why this priority

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

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	2005-03-01
Last modified	2026-06-16

Publisher (CNA): MITRE · Vendor: proxytunnel

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

Am I affected?

Timeline

2005-03-01 05:00 UTCPublished CVE record published
2026-06-16 22:06 UTCUpdated Record last modified

proxytunnel proxytunnel DOWNGRADE

Affected: 1.0.6 · 1.1.3 · 1.2.2 · 1.2_.0

Fixed in: no fixed release known

Safe to downgrade to: a release before 1.0.6

1. Check installed version

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

2. No fixed release: DOWNGRADE to a release before 1.0.6 (Debian / Ubuntu)

apt-cache madison proxytunnel sudo apt install proxytunnel=<VERSION_BEFORE_1.0.6> sudo apt-mark hold proxytunnel

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

dnf --showduplicates list proxytunnel sudo dnf downgrade proxytunnel-<VERSION_BEFORE_1.0.6> sudo dnf versionlock add proxytunnel

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-2004-0992?

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

Is CVE-2004-0992 being exploited?

CVE-2004-0992 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-2004-0992 affect?

CVE-2004-0992 affects proxytunnel. Severity is high (CVSS 10.0). Format string vulnerability in the -a option (daemon mode) in Proxytunnel before 1.2.3 allows remote attackers to execute arbitrary code via format string specifiers in an invalid proxy answer.

How urgent is CVE-2004-0992?

Priority 58/100. Critical severity; EPSS top 9%: very likely to be exploited

Related CVEs

CVE-2004-2440 LOW 2.1 DOWNGRADE Unspecified vulnerability in cmdline.c in proxytunnel 1.1.3 and earlier allows local users to obtain proxy cre

References

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