CVE-1999-1537: Medium severity Microsoft Internet Information Server vulnerability
IIS 3.x and 4.x does not distinguish between pages requiring encryption and those that do not, which allows remote attackers to cause a denial of service (resource exhaustion) via SSL requests to the HTTPS port for normally unencrypted files, which will cause IIS to perform extra work to send the files over SSL.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Configuration
Remove HTTPS bindings or disable SSL for files/pages that do not require encryption so IIS does not perform extra work sending normally-unencrypted files over SSL.
Microsoft Internet Information Services (IIS) 3.x and 4.x HTTPS/SSL binding = disable HTTPS for content that does not require encryption - Compensating control
Restrict or filter access to the HTTPS port (TCP 443) at the network perimeter (firewall, load balancer, or WAF) to trusted IPs and/or implement rate-limiting to mitigate resource-exhaustion attacks via SSL requests.
Event History
Frequently Asked Questions
What is the severity of CVE-1999-1537?
CVE-1999-1537 is classified as a denial of service vulnerability due to the resource exhaustion it can cause.
How do I fix CVE-1999-1537?
To mitigate CVE-1999-1537, ensure that SSL is only applied to pages that require encryption and consider upgrading to a more secure version of IIS.
Which versions of IIS are affected by CVE-1999-1537?
CVE-1999-1537 affects Microsoft Internet Information Server versions 3.0 and 4.0.
What kind of attacks can CVE-1999-1537 facilitate?
CVE-1999-1537 can facilitate denial of service attacks via unsolicited SSL requests to unencrypted files.
Is there a workaround for CVE-1999-1537?
A possible workaround for CVE-1999-1537 is to restrict access to the HTTPS port for files that do not require SSL.