Opera is a multi-platform web browser.
The Opera browser can cause a buffer allocated on the heap to overflow under certain HREFs when rendering HTML. The mail system is also deemed vulnerable and an attacker can send an email containing a malformed HREF, or plant the malicious HREF on a web site.
Certain HREFs can cause a buffer allocated on the heap to overflow when rendering HTML which can allow arbitrary bytes on the heap to be overwritten which can result in a system compromise.
There is no known workaround at this time.
Users are encouraged to perform an 'emerge sync' and upgrade the package to the latest available version. Opera 7.22 is recommended as Opera 7.21 is vulnerable to other security flaws. Specific steps to upgrade:
# emerge sync
# emerge -pv '>=www-client/opera-7.22'
# emerge '>=www-client/opera-7.22'
# emerge clean