Opera denies refusing to patch critical vulnerability

Opera Software has released an update for its desktop browser in order to address a critical vulnerability in its handling of Scalable Vector Graphics (SVG) files, disclosed a week ago. The company denies refusing to patch the flaw when it was brought to its attention earlier this year.

Security researcher José A. Vázquez stirred controversy at the beginning of last week when he released proof-of-concept exploit code for an unpatched vulnerability in Opera.

Making security issues public without notifying affected vendors in advance is generally frowned upon in the security community, but is not particularly uncommon. However, in this case, the researcher claims to have tried acting responsibly without success.

"In this post, I do the release of an issue that I discovered 362 days ago and it was reported to Opera using the SSD program (SecuriTeam Secure Disclosure), but they have decided not to fix it," Vázquez said on his blog on Oct. 10.

The issue stems from an error in Opera's SVG handling code which can be exploited to execute arbitrary code by tricking victims into loading specially crafted SVG images with malformed fonts.

Opera admits being alerted about the flaw six months ago, as part of a larger report, but, it claims that it couldn't replicate the issue at the time. According to the vendor, its attempts to obtain more information from the researcher at the time weren't successful.

"In this case, the issue had only been confirmed for older versions of Opera, not the current version, at the time of it being reported, and the recently published information contained details that were not included in the original report, and which appear to be relevant to reproducing the issue," Opera quality assurance engineer Sigbjørn Vik said Wednesday.

"With our release today of Opera 11.52, we have a fix available for this issue, less than a week after being made aware of the relevant details. [...] We recommend that all Opera users download and install this newest version," he said.

SVG handling vulnerabilities are common and most browser vendors have dealt with this type of issue at one point or another. Such flaws are usually discovered with the help of automated programs called fuzzers which feed malformed input to SVG parsers in the hope of triggering expoloitable crashes.

The latest Google Chrome stable update contained a patch for a flaw involving SVG fonts, while a critical SVG vulnerability was patched in Firefox 6.

In addition to addressing the SVG vulnerability, Opera 11.52 also contains fixes for non-security issues with BitTorrent downloads, HTML5 videos and X-Frame-Options error pages.