Firefox fixes a flurry of flaws in the first of two releases this month

The most recent full new model of Firefox is out, marking the primary of two “month-to-month” upgrades you’ll see this month.

Simply as there can be a blue moon in August 2023 (that’s the title utilized to a second full moon in the identical calendar month, quite than reference to an atmospheric phenomenon that makes the moon appear blue, in case you ever questioned), there can be a blue Firefox too.

Firefox model upgrades occur each 28 days, quite than as soon as a month, so every time a launch comes out early sufficient within the month, there can be a second improve squeezed in on the finish.

Teachable moments

Luckily there are not any zero-day vulnerabilities this time, however the next bug experiences caught our eye:

CVE-2023-4045: Offscreen Canvas might have bypassed cross-origin restrictions. One webpage might peek at pictures displayed in one other web page from a unique web site. The identical-origin coverage in browsers is meant to limit the attain of HTML and JavaScript content material from web site X so it might entry kinds, knowledge, pictures, cookies and the like provided that they too initially got here from web site X. Any methods that may bypass this same-origin safety can theoretically be used to slurp up so-called cross-origin knowledge that shouldn’t be accessible in any respect.
CVE-2023-4047: Potential permissions request bypass through clickjacking. A rogue web page might tempt you to click on on a carefully-placed merchandise, equivalent to a completely innocent-looking button, just for the enter to register as a click on in a safety dialog that didn’t pop up in time so that you can see. Probably dangerous permissions, equivalent to accessing your location, sending notifications, activating the microphone and so forth, aren’t presupposed to be granted till you’ve seen and acted on a transparent warning from the browser itself.
CVE-2023-4048: Crash in DOMParser resulting from out-of-memory situations. DOM is brief for doc object mannequin, and the DOMParser is the code that deconstructs the HTML in an internet web page that the browser is rendering for show, turning it into a giant JavaScript knowledge object wherein all the person parts equivalent to paragraphs, headings, pictures, desk gadgets and so forth could be accessed and modified programmatically. Advanced pages usually flip into giant JavaScript constructions that may take a number of reminiscence to determine after which to retailer. Assume {that a} decided attacker might intentionally eat up reminiscence by loading a variety of giant however harmless pages, after which predictably set off a crash utilizing a crafted HTML file that will get fetched at simply the unsuitable time.
CVE-2023-4050: Stack buffer overflow in StorageManager. That is an old-school stack overflow that doesn’t get detected in time by Firefox itself, and will subsequently result in a crash as an alternative of a managed shutdown. All crashes brought on by the wrong circulation of execution in a program (equivalent to leaping to any invalid reminiscence handle X) must be thought of doubtlessly exploitable. Assume {that a} decided attacker might determine affect the worth of X, and thereby acquire no less than some measure of malevolent management over the crash.
CVE-2023-4051: Full display screen notification obscured by file open dialog. Fullscreen mode is all the time a bit dangerous, as a result of it provides the net web page you’re viewing exact management over each pixel on the display screen. Because of this there are not any components of the show that may be modified solely by the browser itself or solely by the working system. That’s why browsers intention to warn you earlier than giving over the entire show to an internet web page, so that popups that appear like official browser or working system dialogs is likely to be no such factor.
CVE-2023-4057 and CVE-2023-4058: Reminiscence security bugs fastened in varied Firefox variations. As regular, though none of those bugs was clearly exploitable, they usually had been fastened proactively anyway, Mozilla has rated them “Excessive” and given its ever-frank evaluation that “we presume that with sufficient effort a few of these might have been exploited to run arbitrary code.”

What to do?

The brand new variations you might be in search of after updating are:

Firefox 116 should you’re on the newest model.
Firefox ESR 115.1 if you’re a person of the Prolonged Help Launch, which incorporates safety patches however doesn’t add new options. (Including 115+1 from the ESR model quantity tells you that this launch aligns with Firefox 116 for safety fixes, though its characteristic set aligns with Firefox 115.)
Thunderbird 115.1 should you use Mozilla’s e-mail software program, which incorporates the Firefox net shopping code for rendering HTML emails and viewing emailed net hyperlinks.

Head to Firefox -> About Firefox in case you have a Mac, or Assist -> About Firefox on different platforms.

Dont neglect, should you use one of many BSDs or a Linux distro, that your Firefox launch is likely to be managed by the distro itself, so test along with your supplier for updates.