CVE-2003-0190: OpenSSH-portable (OpenSSH) 3.6.1p1 and earlier with PAM support enabled immediately sends an error message whe

Q: How do I fix CVE-2003-0190?

openssh: upgrade to 3.6.1; openpkg: downgrade or apply the listed mitigation; scalance x204rna ecc firmware: upgrade to 3.2.7. Exact commands for each OS are on this page.

Q: Is CVE-2003-0190 being exploited?

CVE-2003-0190 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2003-0190 affect?

CVE-2003-0190 affects openssh, openpkg, scalance x204rna ecc firmware. Severity is medium (CVSS 5.0). OpenSSH-portable (OpenSSH) 3.6.1p1 and earlier with PAM support enabled immediately sends an error message when a user does not exist, which allows remote attackers to determine valid usernames via a timing attack.

Q: How urgent is CVE-2003-0190?

Priority 52/100. EPSS top 1%: very likely to be exploited; Public exploit reference; On your watchlist

This week

MEDIUM 5.0WATCHLISTUPGRADEDOWNGRADEUPGRADE

CVE-2003-0190 is a medium-severity flaw (CVSS 5.0) affecting openssh, openpkg, scalance x204rna ecc firmware. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

OpenSSH-portable (OpenSSH) 3.6.1p1 and earlier with PAM support enabled immediately sends an error message when a user does not exist, which allows remote attackers to determine valid usernames via a timing attack.

Why this priority

EPSS top 1%: very likely to be exploited
Public exploit reference
On your watchlist

A fixed release or distro patch exists.

Risk facts

CVSS score	5.0 (Medium)
EPSS exploit chance	76.8% (top 1%)
CISA exploited list	No
Weakness	CWE-203
Published	2003-05-12
Last modified	2026-06-16

Publisher (CNA): MITRE · Vendor: openbsd · openpkg · siemens

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

Am I affected?

Timeline

2003-05-12 04:00 UTCPublished CVE record published
2026-06-16 22:01 UTCUpdated Record last modified

openbsd openssh UPGRADE

Affected: < 3.6.1 · 3.6.1 p1

Fixed in: 3.6.1

Safe to downgrade to: no unaffected older release

1. Check installed version

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

2. UPGRADE to 3.6.1 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade openssh

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade openssh

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

openpkg openpkg DOWNGRADE

Affected: 1.2 · 1.3

Fixed in: no fixed release known

Safe to downgrade to: a release before 1.2

1. Check installed version

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

2. No fixed release: DOWNGRADE to a release before 1.2 (Debian / Ubuntu)

apt-cache madison openpkg sudo apt install openpkg=<VERSION_BEFORE_1.2> sudo apt-mark hold openpkg

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

dnf --showduplicates list openpkg sudo dnf downgrade openpkg-<VERSION_BEFORE_1.2> sudo dnf versionlock add openpkg

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.

siemens scalance x204rna ecc firmware UPGRADE

Affected: < 3.2.7

Fixed in: 3.2.7

Safe to downgrade to: no unaffected older release

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

siemens scalance x204rna firmware UPGRADE

Affected: < 3.2.7

Fixed in: 3.2.7

Safe to downgrade to: no unaffected older release

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

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: OpenSSH/PAM 3.6.1p1 - 'gossh.sh' Remote Users Ident
Exploit-DB: OpenSSH/PAM 3.6.1p1 - Remote Users Discovery Tool
Exploit-DB: Portable OpenSSH 3.6.1p-PAM/4.1-SuSE - Timing Attack
Metasploit: SSH Username Enumeration

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-2003-0190?

openssh: upgrade to 3.6.1; openpkg: downgrade or apply the listed mitigation; scalance x204rna ecc firmware: upgrade to 3.2.7. Exact commands for each OS are on this page.

Is CVE-2003-0190 being exploited?

CVE-2003-0190 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-2003-0190 affect?

CVE-2003-0190 affects openssh, openpkg, scalance x204rna ecc firmware. Severity is medium (CVSS 5.0). OpenSSH-portable (OpenSSH) 3.6.1p1 and earlier with PAM support enabled immediately sends an error message when a user does not exist, which allows remote attackers to determine valid usernames via a timing attack.

How urgent is CVE-2003-0190?

Priority 52/100. EPSS top 1%: very likely to be exploited; Public exploit reference; On your watchlist

Software pages

OpenSSH vulnerabilities · Siemens vulnerabilities

Related CVEs

CVE-2026-55655 MEDIUM 5.0 MITIGATE MITIGATE A flaw was found in OpenSSH
CVE-2026-55653 MEDIUM 4.3 MITIGATE MITIGATE A flaw was found in OpenSSH
CVE-2026-60002 HIGH 7.7 UPGRADE ssh in OpenSSH before 10.4 can have a use-after-free when a server changes its host key during a key re-exchan
CVE-2026-60001 MEDIUM 6.5 UPGRADE sshd in OpenSSH before 10.4 does not always honor the minimum authentication delay.
CVE-2026-60000 LOW 3.7 UPGRADE sshd in OpenSSH before 10.4 allows remote attackers to cause a denial of service (resource consumption from ex

References

← Back to latest CVEs