cbcvebase.
CVE-2000-0649
published 2000-07-13

CVE-2000-0649: IIS 4.0 allows remote attackers to obtain the internal IP address of the server via an HTTP 1.0 request for a web page which is protected by basic…

PriorityP421low2.6CVSS 2.0
AVNACHAuNCPINAN
EXPLOIT
EPSS
76.56%
99.5th percentile
IIS 4.0 allows remote attackers to obtain the internal IP address of the server via an HTTP 1.0 request for a web page which is protected by basic authentication and has no realm defined.

Affected

4 ranges
VendorProductVersion rangeFixed in
microsoftinternet_information_server
microsoftinternet_information_server
microsoftinternet_information_services
microsoftinternet_information_services

Detection & IOCsextracted from sources · hover to see the quote

commandHEAD /directory HTTP/1.0
commandPROPFIND
  • Detect HTTP 1.0 requests to Basic-auth protected resources with no realm defined; IIS responds with a 401 containing 'WWW-Authenticate: Basic realm=""' (empty realm), which leaks the internal IP in the response body.
  • Monitor for HTTP PROPFIND requests to IIS servers; the response HREF header may disclose the internal IP address.
  • Monitor for HTTP WRITE and MKCOL method requests against IIS, which may also expose the internal IP address.
  • Detect HTTP requests made with an empty Host header to IIS servers, which can trigger internal IP disclosure.
  • On IIS 7+, internal IP disclosure via this CVE occurs when the alternateHostName is not set or misconfigured; detection should cover modern IIS versions, not just IIS 4.0/5.x.
  • ·The vulnerability affects IIS even when placed behind a firewall or NAT; the true internal IP is still disclosed in the 401 response regardless of network topology.
  • ·Scope is broader than originally documented; the Metasploit module covers IIS 2.0 through 5.1 for CVE-2000-0649, but also targets IIS 7+ via misconfigured alternateHostName and PROPFIND leakage.
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