CVE-1999-1231

CVE-1999-1231 is a medium-severity vulnerability in Ssh Ssh2 with a CVSS 2.0 base score of 5.0. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low.

Key facts

Description

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.

Frequently asked questions

What is CVE-1999-1231?
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.
How severe is CVE-1999-1231?
CVE-1999-1231 has a CVSS 2.0 base score of 5.0, rated medium severity.
Is CVE-1999-1231 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (71st percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-1999-1231?
CVE-1999-1231 primarily affects Ssh Ssh2. In total, 13 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-1999-1231?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-1999-1231 published?
CVE-1999-1231 was published on 1999-06-09 and last updated on 2026-06-16.

References

Affected products (13)

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