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Vulnerability record · CVE-1999-0191 · published 1 September 1997

CVE-1999-0191: IIS newdsn.exe CGI script allows remote file overwrite

Microsoft · Internet Information Server

The IIS newdsn.exe CGI script permits remote users to overwrite files on the server. Because the script is reachable over the network without authentication, an attacker can tamper with or destroy files the web server process can write to. The record is old and thin: no affected version list, no patch reference, and only a generic CWE mapping are provided.

6.4 CVSS 2.0 Medium EPSS 53% · top 1.0%
6.4CVSS 2.0 base score
53%EPSS exploitation probability, 30 days
NoNot in CISA KEV
1Affected product versions listed by NVD
2References
16 Jun 2026Last modified by NVD

Description

IIS newdsn.exe CGI script allows remote users to overwrite files.

AV:N/AC:L/Au:N/C:P/I:P/A:N

Automated analysis

Generated by VULONE's analysis model from the NVD record, CISA KEV and EPSS data on 20 September 2026. Confidence: low.

medium priorityRemote unauthenticated file overwrite is serious, but the CVSS 2.0 score is 6.4 (medium) and the record lacks affected versions and patch details.

What it is

The IIS newdsn.exe CGI script permits remote users to overwrite files on the server. Because the script is reachable over the network without authentication, an attacker can tamper with or destroy files the web server process can write to. The record is old and thin: no affected version list, no patch reference, and only a generic CWE mapping are provided.

Impact

An attacker gains the ability to overwrite arbitrary files writable by the IIS service account, which can corrupt content or configuration and potentially enable further compromise. Integrity is affected; confidentiality and availability are not rated as impacted in the CVSS vector.

Attack surface

Reached remotely over the network via HTTP requests to the newdsn.exe CGI script, per the AV:N vector. The vector shows Au:N, so no authentication is required, and no user interaction is indicated.

Exploitation

Not listed in CISA KEV and no exploit tags appear in the references, but EPSS is high at roughly 0.53 (99th percentile), indicating elevated predicted exploitation activity. No public exploit details are given in the record.

What to do

  • Apply the vendor patch or upgrade to a supported IIS release; no patch reference is included in this record, so consult Microsoft advisories for the affected version.
  • Remove or disable the newdsn.exe CGI script if it is not required.
  • Restrict the IIS service account's write permissions to only the directories it needs.
  • Block or filter requests to legacy CGI scripts such as newdsn.exe at the web server or WAF.

Detection

  • Monitor web server logs for requests to newdsn.exe, especially from unexpected sources.
  • Alert on file writes or modifications in web-accessible directories by the IIS service account.
  • Baseline and integrity-check web content and configuration files for unexpected changes.

This assessment is produced automatically and is not human-reviewed. Verify against the vendor advisory before acting on it.

Affected products

1 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
http://www.osvdb.org/275
http://www.osvdb.org/275

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Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

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Source: NIST National Vulnerability Database (record CVE-1999-0191), CISA KEV, FIRST EPSS (scores of 2026-09-26). This page is refreshed as NVD updates the record.