The vulnerability at least led to potential security issues at one of Verisign's customer (a bank). The vulnerability was discovered using publicly available information. Comodo definitely was careful in the wording of this press release, no details of the vulnerability was released. They also stated that they followed CCSS's (Common Computing Security Standards Forum) guideline in releasing the vulnerability information.
While it seems that Comodo is doing everything right, it still brings the question - Should you test your competitor's products/ stuff? And - How do you handle the announcement so it doesn't look like you are doing leveraging your competitor's security weakness in marketing? There are no good answers to those questions, it's all dependent on the situation. It's all a very fine line. It's hard to balance the bragging rights by the finder of a vulnerability before the announcement of actual vulnerability by the vendor. In some cases, vulnerabilities are never released by the vendor. Bottom line, credit to the finder of vulnerability should be given.
The link for this article located at SANS is no longer available.
