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CVE-1999-0874· NVD / CVE Program· CNA mitre

Buffer overflow in IIS 4.0 allows remote attackers to cause a denial of service via a malformed request for files with .HTR, .IDC, or .STM e

Noroxi assessment

Priority: This week (action score 62/100)

  • A ready-made attack module is public (Metasploit); exploiting it takes no special expertise.
  • Public proof-of-concept code exists (Exploit-DB); there is no record of exploitation in the wild.
  • Probability of exploitation in the next 30 days: 74.6% (FIRST EPSS); higher than 99.4% of all records.
  • No special conditions are required; it is repeatable.
  • According to the record, no fixed version is available yet.

Don’t wait for the next maintenance window. Until a fix is released, restrict access to the affected component and follow the vendor's advisory.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

Buffer overflow in IIS 4.0 allows remote attackers to cause a denial of service via a malformed request for files with .HTR, .IDC, or .STM extensions.

CriticalCVSS 10.0 · v2.0—Weaponized No fix recorded
Published
Jun 16, 1999
Updated
Jun 16, 2026
EPSS
74.6% · 99th percentile

Report tools

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Action score

62

This week

Don’t wait for the next maintenance window.

CVSS
40 / 40 · 10.0 / 10
CISA KEV
0 / 30 · Not listed
EPSS
22 / 30 · 74.6%

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • Weaponized exploit exists
  • No fixed version yet

If any of these changes, we'll tell you in the daily email digest.

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When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
microsoftinternet information server
microsoftwindows 2000
microsoftwindows nt

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • microsoft internet information server4.0
  • microsoft windows 2000all versions
  • microsoft windows ntall versions
  • microsoft windows nt4.0

Same product

microsoft: all records

Other highest-scoring records for the same primary product.

  • CVE-2009-3023Buffer overflow in the FTP Service in Microsoft Internet Information Services (IIS) 5.0 through 6.0 allows remote authenticated users to exe
    63This week
  • CVE-2008-0075Unspecified vulnerability in Microsoft Internet Information Services (IIS) 5.1 through 6.0 allows remote attackers to execute arbitrary code
    57Plan
  • CVE-2001-0333Directory traversal vulnerability in IIS 5.0 and earlier allows remote attackers to execute arbitrary commands by encoding ..
    57Plan

Published before and after this one in the same product

  • ← EarlierCVE-1999-0739May 7, 1999 · The codebrws.asp sample file in IIS and Site Server allows remote attackers to read arbitrary files.
    29Monitor
  • ← EarlierCVE-1999-0229May 12, 1999 · Denial of service in Windows NT IIS server using ..\..
    22Monitor
  • Later →CVE-1999-1478Jul 6, 1999 · The Sun HotSpot Performance Engine VM allows a remote attacker to cause a denial of service on any server running HotSpot via a URL that inc
    25Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

No fix version is recorded for this entry. Check the references for vendor advisories.

Exploit status

Weaponized

A ready exploit tool or active in-the-wild use is known for this vulnerability. This should be your top priority.

Evidence

  • Metasploit module ×1
  • Exploit-DB entry ×5

Noroxi does not host or link to exploit code. Metasploit module names and Nuclei template ids are shown (names, not code); Exploit-DB entries and PoC repositories are given as counts only.

Public exploit evidence
SourceKindDate
Exploit-DB entryremote1999-06-15
Exploit-DB entryremote2010-04-30
Exploit-DB entryremote1999-06-15
Exploit-DB entryremote1999-06-15
Exploit-DB entryremote1999-06-15
Metasploit moduleexploit/windows/iis/ms02_018_htrMS02-018 Microsoft IIS 4.0 .HTR Path Overflowexploit2002-04-10

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

  1. First PoC-1 d
  2. Published
  3. Metasploit+1029 d
  4. TodayOct 20, 2026+9989 d
EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

  • No special conditions are required; it is repeatable.

If successful

Confidentiality
C · data can be read
Integrity
C · data or configuration can be modified
Availability
C · the service can be disrupted
Attack complexity
Low
Confidentiality impact
C
Integrity impact
C
Availability impact
C

Weakness class (CWE)

CWE-119 · Improper Restriction of Operations within the Bounds of a Memory Buffer

CVSS vector

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

nvd-primary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

ATT&CK techniques

—

Change log

No changes recorded on tracked fields yet. Score, KEV, exploit maturity and fix status changes appear here.

References

Show all references (4 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records