CVE-2003-0190
MediumPublic exploitOpenSSH-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.
Published May 12, 2003 · Updated Aug 4, 2026 · Also known as DEBIAN-CVE-2003-0190
Key Facts
Patch immediately- CVE-2003-0190 is a medium-severity vulnerability (CVSS 5.0 v2) affecting Openssh (Openbsd), Openpkg, Scalance X204rna Ecc Firmware (Siemens) and 2 more products.
- It is not listed in any known-exploited vulnerabilities catalog. Public exploit code is available.
- EPSS estimates a 77% probability of exploitation in the next 30 days.
- Fixed versions are available, including Openssh 3.6.1, Openssh 1:3.8.1p1-8.sarge.4, rootio-openssh 1:3.8.1p1-8.sarge.4.
- Brandefense priority: patch immediately, because it is very likely to be exploited soon.
CVSS v2
5.0
AV:N/AC:L/Au:N/C:P/I:N/A:N
EPSS (30-day exploit likelihood)
77%
Higher than 99.5% of all scored CVEs
Exploited in the wild
No known
Not in a known-exploited catalog
Public exploit code
Available
Proof-of-concept or weaponized module
Get the full CVE-2003-0190 brief as a PDF
Every affected product and fixed release, exploitation status and a first 24 hours response checklist, emailed within minutes.
Description
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.
Affected Products
20 affected entries in total| Product | Affected versions | Fixed in |
|---|---|---|
| OpensshOpenbsd | 3.6.1-p1 | 3.6.1 |
| OpenpkgOpenpkg | 1.2, 1.3 | n/a |
| Scalance X204rna Ecc FirmwareSiemens | See advisory | 3.2.7 |
| Scalance X204rna FirmwareSiemens | See advisory | 3.2.7 |
| rootio-opensshrootio | See advisory | 1:3.8.1p1-8.sarge.4 |
Patched Releases
Openssh
3.6.1, 1:3.8.1p1-8.sarge.4
rootio-openssh
1:3.8.1p1-8.sarge.4
Scalance X204rna Ecc Firmware
3.2.7
Scalance X204rna Firmware
3.2.7
Timeline
Publicly disclosed
May 12, 2003
Last updated
Aug 4, 2026
Weakness Type
- CWE-203 Observable Discrepancy
References
- advisory20030430 OpenSSH/PAM timing attack allows remote users identification
- advisory20030806 [OpenPKG-SA-2003.035] OpenPKG Security Advisory (openssh)
- advisoryRHSA-2003:222
- advisoryRHSA-2003:224
- advisoryhttps://cert-portal.siemens.com/productcert/pdf/ssa-412672.pdf
FAQ
Common Questions.
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.
Affected: Openssh (Openbsd) versions 3.6.1-p1; Openpkg versions 1.2, 1.3; Scalance X204rna Ecc Firmware (Siemens), among others. The full list is in the CVE brief.
It is not listed in any known-exploited vulnerabilities catalog.
No, it is not currently listed in the CISA Known Exploited Vulnerabilities catalog.
Public exploit code is available.
Fixed versions are available, including Openssh 3.6.1, Openssh 1:3.8.1p1-8.sarge.4, rootio-openssh 1:3.8.1p1-8.sarge.4.
Brandefense priority: patch immediately, because it is very likely to be exploited soon.
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