Mozilla's Thunderbird e-mail client was not affected by the vulnerability, it said.
The fix comes on the heels of release of Firefox version 18.104.22.168, which was aimed at fixing a handful of previously documented security problems in the browser.
Firefox has also come under criticism from independent researchers, including Polish vulnerability expert Michael Zalewski, regarding several other classes of vulnerabilities, some of which are related to new spoofing and phishing threats aimed at the software.
Window Snyder, chief security officer at Mozilla, said that her company is receiving more feedback than ever from customers concerned about browser security issues and promised that the firm is working hard to address any problems and set those fears at ease.
Because the browser is one of the most important applications on today's computers -- and a growing number of mobile devices --it will likely remain a focal point for attacks and security researchers, but that comes with the territory, she said
Mozilla has decided against using the Microsoft approach of monthly patch releases in favour of getting security patches distributed to users as problems emerge.
"It's important for us to focus on how quickly the fixes are made available, we try to focus on that and keep the window of risk as short as possible," Snyder said in a recent interview with InfoWorld.
Unlike other products that can be significantly bolstered for the sake of protecting against attacks, the very nature of the Web-viewing programs makes it much harder to limit potential weak points, said Chenxi Wang, an analyst with Forrester Research.
"The browser is of general use, it's not something specially-purposed that can be hardened, it has to be able to handle different types of sites and content, and it has to allow plug-ins," Wang said.
Grant Gross of the IDG News Service contributed to this report.