New 0-day vulnerability has been discovered in Opera, which can be utilised to gain control of a user’s system. The vulnerability is known to affect Opera 10.10 and Opera 10.50 for Windows (other versions may be affected too) and a proof of concept submitted by Marcin Ressel is available here.
Secunia has categorised the vulnerability as highly critical. Apparently, the issue is caused due to a buffer overflow error, which can be triggered by a malformed HTTP “Content-Length:” header. Successful exploitation of the vulnerability may permit the execution of arbitrary code on the user’s system.
At the moment, no solution is available for the exploit. Until Opera Software patches this vulnerability, all Opera users should be cautious while browsing untrusted websites.
Update: This vulnerability may not be as dangerous as previously believed to be. Haavard K. Moen from Opera Software indicated that this vulnerability is not exploited. In other words all it can do is crash Opera. Execution of malicious code or gaining control of the user’s system is not possible.