Symantec Thursday said that "suspicious behavior" by a captured exploit had led it to mistakenly conclude that the most up-to-date standalone versions of Adobe System's Flash Player are vulnerable to ongoing attacks from Chinese servers.
But a Symantec researcher said earlier Thursday that Flash Player 18.104.22.168, the currently-available version of the popular multimedia player, is not vulnerable to the ongoing attacks. Just yesterday, Ben Greenbaum, a senior research manager in Symantec's security response group, had claimed that while Flash Player 22.214.171.124 plug-ins were safe, standalone editions of the program were not.
"All versions Version 126.96.36.199 on all platforms, plug-ins and standalone, are not vulnerable," Greenbaum said Thursday.
The switch was the third change in Symantec's analysis in the last two days.
On Tuesday, Symantec first warned that legitimate Web sites were redirecting unwitting users to one of several Chinese servers, which in turn were trying multiple exploits, including some aimed at Flash Player. Then, Symantec said that older versions of the Adobe software -- version 188.8.131.52, which was replaced in early April -- and the current 184.108.40.206 could be successfully exploited.
Based on that analysis, Symantec dubbed the vulnerability a "zero-day" bug, meaning it was unpatched, and dangerous to anyone with Flash installed.
Later on Tuesday, however, Symantec backtracked from the zero-day label. "Originally, it was believed that this issue was unpatched and unknown, but further technical analysis has revealed that it is very similar to the previously reported Adobe Flash Player Multimedia File Remote Buffer Overflow Vulnerability (BID 28695), discovered by Mark Dowd of IBM," Symantec said.
Even so, Greenbaum maintained yesterday that while the vulnerability wasn't new, the in-the-wild exploit was effective against standalone versions of Flash Player 220.127.116.11. "Not all the versions are patched correctly," he said Wednesday.
Thursday, however, Greenbaum said that Symantec had come to the erroneous conclusion based on tests of the standalone Linux version of Flash Player 18.104.22.168. "While testing against the latest [Linux] version, we saw behaviors consistent with a successful exploit that failed to deliver the payload," he explained Thursday. "[But] the exploit was not, in fact, successful against the latest version."