CVE-2003-0783: Multiple buffer overflows in hztty 2.0 allow local users to gain root privileges.

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HIGH 7.2DOWNGRADE

CVE-2003-0783 is a high-severity flaw (CVSS 7.2) affecting hztty. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Multiple buffer overflows in hztty 2.0 allow local users to gain root privileges.

Why this priority

High severity
Public exploit reference

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

Risk facts

CVSS score	7.2 (High)
EPSS exploit chance	1.1% (top 33%)
CISA exploited list	No
Published	2003-10-06
Last modified	2026-06-16

Publisher (CNA): MITRE · Vendor: yongguang zhang

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

Am I affected?

Timeline

2003-10-06 04:00 UTCPublished CVE record published
2026-06-16 22:02 UTCUpdated Record last modified

yongguang zhang hztty DOWNGRADE

Affected: 2.0

Fixed in: no fixed release known

Safe to downgrade to: a release before 2.0

1. Check installed version

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

2. No fixed release: DOWNGRADE to a release before 2.0 (Debian / Ubuntu)

apt-cache madison hztty sudo apt install hztty=<VERSION_BEFORE_2.0> sudo apt-mark hold hztty

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

dnf --showduplicates list hztty sudo dnf downgrade hztty-<VERSION_BEFORE_2.0> sudo dnf versionlock add hztty

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.

Public exploits and detection

Public code exists for this CVE. Treat unpatched systems as at risk, and only run PoCs in a lab.

Exploit-DB: hztty 2.0 (RedHat 9.0) - Local Privilege Escalation

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-2003-0783?

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

Is CVE-2003-0783 being exploited?

CVE-2003-0783 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-2003-0783 affect?

CVE-2003-0783 affects hztty. Severity is high (CVSS 7.2). Multiple buffer overflows in hztty 2.0 allow local users to gain root privileges.

How urgent is CVE-2003-0783?

Priority 47/100. High severity; Public exploit reference

Related CVEs

CVE-2005-0019 MEDIUM 4.6 DOWNGRADE Unknown vulnerability in hztty 2.0 and earlier allows local users to execute arbitrary commands.

References

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