Adobe has warned of attacks on a zero-day flaw in its Reader, Acrobat and Flash applications.
The company has not released a patch, but has issued a workaround for IT administrators to ward off intruders. Danish security analysts Secunia rated the flaw as extremely critical.
Adobe said in a security advisory that the vulnerability could cause a crash and potentially allow an attacker to take control of the affected system.
"There are reports that this vulnerability is being actively exploited in the wild against Adobe Reader and Acrobat 9.x. Adobe is not currently aware of attacks targeting Adobe Flash Player," the firm said.
All versions of Flash on Windows, Mac, Linux and Android are vulnerable, which also affects the Authplay component of Reader and Acrobat 9.x that renders Flash in PDFs.
A full patch for Reader and Acrobat is expected by 15 November and the Flash flaw will be fixed a week earlier, according to Adobe.
Adobe released a fix yesterday for a previous flaw in Shockwave for Windows and Macintosh.
Geoengineering on the sea floor near glaciers would form a new ice shelf to prevent melting
Alterations in capillary blood flow can be caused by body position change
Curiosity rover is in 'normal mode' but not transmitting scientific data back to base
NatWest outage comes a day after Barclays' IT systems shut out customers and staff