CVE-1999-1231

Exp

ssh 2.0.12, and possibly other versions, allows valid user names to attempt to enter the correct password multiple times, but only prompts an invalid user name for a password once, which allows remote attackers to determine user account names on the server.

Published: 1999-06-09 Last update: 2026-06-16 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-1999-1231 is rated High Exploit Risk (60.3/100): CVSS Medium severity, with medium exploitation likelihood (EPSS 1.48%). 1 public exploit reference(s) are indexed (Exploit-DB). Public exploits are available—assess exposure, apply mitigations, and prioritize patching.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Public exploit references (Exploit-DB) for CVE-1999-1231

EDB-ID Source Kind Published Link
— nvd_ref exploit_tag Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-1999-1231

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.76% 1.48% +0.71%
2 2026-01-02 0.96% 0.76% -0.20%
3 2025-03-30 — 0.96% —

Full EPSS history (8 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-1999-1231

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
5.0 2.0 MEDIUM
AV:N/AC:L/Au:N/C:P/I:N/A:N Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:N)
No integrity impact.
Availability impact (A:N)
No availability impact.
 10.0 2.9 [email protected]

Weakness enumeration for CVE-1999-1231

Affected software / configurations for CVE-1999-1231

Vendor Product Version Raw CPE
ssh ssh2 2.0 cpe:2.3:a:ssh:ssh2:2.0:*:*:*:*:*:*:*
ssh ssh2 2.0.1 cpe:2.3:a:ssh:ssh2:2.0.1:*:*:*:*:*:*:*
ssh ssh2 2.0.2 cpe:2.3:a:ssh:ssh2:2.0.2:*:*:*:*:*:*:*
ssh ssh2 2.0.3 cpe:2.3:a:ssh:ssh2:2.0.3:*:*:*:*:*:*:*
ssh ssh2 2.0.4 cpe:2.3:a:ssh:ssh2:2.0.4:*:*:*:*:*:*:*
ssh ssh2 2.0.5 cpe:2.3:a:ssh:ssh2:2.0.5:*:*:*:*:*:*:*
ssh ssh2 2.0.6 cpe:2.3:a:ssh:ssh2:2.0.6:*:*:*:*:*:*:*
ssh ssh2 2.0.7 cpe:2.3:a:ssh:ssh2:2.0.7:*:*:*:*:*:*:*
ssh ssh2 2.0.8 cpe:2.3:a:ssh:ssh2:2.0.8:*:*:*:*:*:*:*
ssh ssh2 2.0.9 cpe:2.3:a:ssh:ssh2:2.0.9:*:*:*:*:*:*:*
ssh ssh2 2.0.10 cpe:2.3:a:ssh:ssh2:2.0.10:*:*:*:*:*:*:*
ssh ssh2 2.0.11 cpe:2.3:a:ssh:ssh2:2.0.11:*:*:*:*:*:*:*
ssh ssh2 2.0.12 cpe:2.3:a:ssh:ssh2:2.0.12:*:*:*:*:*:*:*

References for CVE-1999-1231

cvelogic Threat Intelligence