CVE-2000-0246: Medium severity Microsoft Commercial Internet System vulnerability
IIS 4.0 and 5.0 does not properly perform ISAPI extension processing if a virtual directory is mapped to a UNC share, which allows remote attackers to read the source code of ASP and other files, aka the "Virtualized UNC Share" vulnerability.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Configuration
Do not map virtual directories to UNC shares. Remove existing UNC share mappings or remap those virtual directories to local file system paths on the web server so ISAPI extension processing does not occur from a UNC share.
Microsoft Internet Information Services (IIS) virtual_directory_unc_mapping = disabled / use local path - Compensating control
If UNC share mappings cannot be removed immediately, restrict access to the UNC share and to the IIS site: limit access to the UNC share to only required service accounts and trusted hosts, and restrict access to the affected IIS sites or management interfaces via firewall/ACL to trusted IP addresses or networks to reduce remote exposure.
Event History
Frequently Asked Questions
What is the severity of CVE-2000-0246?
CVE-2000-0246 is considered a critical vulnerability due to the exposure of sensitive source code.
How do I fix CVE-2000-0246?
To mitigate CVE-2000-0246, ensure that virtual directories are not mapped to UNC shares and apply any relevant patches provided by Microsoft.
What systems are affected by CVE-2000-0246?
CVE-2000-0246 affects Microsoft IIS 4.0 and 5.0, along with several Microsoft Commercial Internet System and Site Server versions.
What type of attack does CVE-2000-0246 enable?
CVE-2000-0246 allows remote attackers to read the source code of ASP and other files on the server.
Is there a workaround for CVE-2000-0246?
A possible workaround for CVE-2000-0246 is to restrict access to virtual directories and avoid using UNC shares.