Specifications

Allaire ColdFusion 4.5.1 Cached File Request DoS Vulnerability

Released May 10, 2000

Affects Allaire ColdFusion Server 4.5.1

Reference http://www.securityfocus.com/bid/1192

Problem

- It is possible to remotely halt the operation of Allaire ColdFusion Server by requesting a cached

file that is no longer stored in memory and contains a <CFCACHE> tag. Other conditions that are

necessary in order to reliably cause a denial of service in this instance are that there are no

running thread request slots available at the time of the cached file request, knowledge of the

timeout period, last cached date/time, and 'Limit Simultaneous Requests' setting (which is by

default, 5), and the use of a load generator or DoS tool.

- Most of these requirements can be met by performing various reconnaissance actions against the

server, or ignored by making relatively safe assumptions, taking into account the default settings

and the traffic levels/popularity of the server.

- The default number of cached file requests that ColdFusion Server can handle is 5. Therefore, 6

simultaneous requests for the same cached file no longer in memory could possibly cause the

server to stop responding and will require to be restarted in order to regain normal functionality.

SAFER

- Allaire released patches on January 4, 2000 regarding potential information leakage by the

CFCACHE tag, which will also clear up this vulnerability.

UltraBoard DoS Vulnerability

Released May 05, 2000

Affects UltraScripts UltraBoard 1.6

Reference http://www.securityfocus.com/bid/1175

Problem

- UltraBoard 1.6 (and possibly all 1.x versions and the new beta Ultraboard 2000) are vulnerable to

this Denial of Service attack.

- A remote user is able to expend all of the available resources of the webserver by using a

specially devised request to the CGI. This request causes a fork, which will then consume the

processor time and memory of the server.

SAFER

- Typical resource exhaustion attack.

Linux knfsd Denial of Service Vulnerability

Released May 01, 2000

Affects Linux kernel 2.3.x, 2.2.x, 2.1.x

Reference http://www.securityfocus.com/bid/1160

Problem

- Due to inconsistencies in differentiating between signed and unsigned integers within the program,

it becomes possible for a remote, unauthenticated user to cause the knfsd, and NFS service, to be

unavailable.

SAFER

- Upgrading to the latest versions of the 2.2.x (2.2.15-pre20) or 2.2.3 (2.3.99-pre7) kernel will

remedy this problem.