CVE-1999-1591 in the critical feed json
Microsoft Internet Information Services (IIS) server 4.0 SP4, without certain hotfixes released for SP4, does not require authentication cr…
published 1999-12-31 26 y ago modified 2026-06-16 4 mo ago also EUVD-1999-1572
- cvss
- 7.5
- version 2.0, NVD
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 11.3%
- EPSS 11.3% chance of exploitation in 30 days, percentile 95%
- public exploits
- 0
- none known
Summary
Microsoft Internet Information Services (IIS) server 4.0 SP4, without certain hotfixes released for SP4, does not require authentication credentials under certain conditions, which allows remote attackers to bypass authentication requirements, as demonstrated by connecting via Microsoft Visual InterDev 6.0.
Exploit prediction
11.27% chance of exploitation in the next 30 days, higher than 95% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| NVD | 2.0 | 7.5 | AV:N/AC:L/Au:N/C:P/I:P/A:P |
References
Sources
- CVE List CVE-1999-1591
- NVD CVE-1999-1591
Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.