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Showing posts tagged with Vulnerabilities & Exploits
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James O'Connor | 16 Feb 2007 08:00:00 GMT | 0 comments

There has been much talk recently about thelaunch of Windows Vista, and one feature in particular: SpeechRecognition. Speech Recognition allows the user to dictate arbitrarytext to the computer (a letter for example) using speech instead of thekeyboard. It also allows the user to carry out normal computing tasksvia a choice of pre-defined commands. There are commands such as"delete that," "press escape key," and "what can I say?" This last oneshows the user what kinds of command they can use in the currentsituation. If Speech Recognition is running, but sleeping, the usersays "start listening" to activate it.

It has been suggested that Speech Recognition could be subverted fornefarious purposes using malicious audio clips. The scenario would beas follows:

• The user is browsing the Web, with Speech Recognition enabled.
• They visit a Web site, with a background audio clip that plays as soon as the site is opened.
• The audio clip contains commands that...

Ben Greenbaum | 13 Feb 2007 08:00:00 GMT | 0 comments

Anybody remember when RTF files were just innocent little things?They were like the big brother of the .txt file, or .txt v2, if youwill. Just characters on a screen, but some of them might be differentfonts or colors or sizes – maybe the occasional clipart. Who would haveguessed they are apparently the most hostile files on the Internet thismonth? "When RTFs Go Bad!…" Okay, perhaps I’m exaggerating, but thismonth Microsoft is patching no less than three vulnerabilities, inseparate applications, that can be exploited via malicious RTF filesthat contain OLE objects.

Several of this month’s patches address issues that have beenexploited already in limited-distribution, targeted attacks. Thecombination of target-specific social engineering and privately heldvulnerability information is becoming more and more widely adopted byattackers with political and industrial motivations. While the "newbreed" of cybercriminals wants to cast as wide a net as possible, wecannot forget that...

Aaron Adams | 08 Feb 2007 08:00:00 GMT | 0 comments

The month of January is already over and, accordingly, so is the Month of Apple Bugs(MoAB). As promised, one advisory was released every day of the month,in some cases addressing numerous vulnerabilities in an application.Unlike the Month of Browser Bugs and Month of Kernel Bugs, this time we saw the interesting twist of a parallel group starting a Month of Apple Fixes.This group was responsible for the release of unofficial run-timepatches for the majority of the issues disclosed, with the exception ofthose affecting the kernel.

The classes of vulnerabilities discovered during the MoAB...

Amado Hidalgo | 07 Feb 2007 08:00:00 GMT | 0 comments

Last week, Microsoft published Security Advisory 932553to warn Windows users of a new vulnerability in Microsoft Office.Security Response has analysed a sample of a malicious Microsoft Excelfile that appears to be exploiting the vulnerability that is hinted atin that Advisory. Fully patched versions of Office 2000, XP, and 2003appear to be vulnerable to this exploit.

Upon opening the malicious Microsoft Excel document, which Symantec now detects as Trojan.Mdropper.Y, it drops a Trojan horse program by using the exploit referenced by CVE-2007-0671 (BID 22383).It proceeds to drop a back door Trojan onto the compromised computer.It then attempts to contact...

Elia Florio | 31 Jan 2007 08:00:00 GMT | 0 comments

We've been getting a lot of requests from people asking what it looks like when your computer is compromised by one of these very limited targeted attacksthat involves any of the recent MS Word zero-day vulnerabilities. Atargeted attack begins with an incoming email that has a .DOC fileattached; a very common event that happens to almost everyone everyday. The email sender looks legitimate (it's spoofed of course!) andthe document name is selected to appeal to the recipient. For example,if the targeted user is an accountant, then the document would looklike a tax certificate or an invoice. For members of governments, itcould appear to be an important communication from a Minister. Forfinance brokers, a stocks analysis and so on...

Targeted attacks are not intended for the masses, so we're nevergoing to see the usual "Very exciting greeting postcard.exe" attachedto those emails. But the big question is: what happens when someoneopens the malicious...

Eric Chien | 30 Jan 2007 08:00:00 GMT | 0 comments

We have received some additional Worddocuments that exploit an unpatched Microsoft Word vulnerability. Thesedocuments are detected as Trojan.Mdropper.X. We believe this is a newvulnerability, making it the fifth currently unpatched Office fileformat vulnerability. While these documents are being used in atargeted attack consistent with previous cases, we have receiveddifferent documents that use this same exploit from multipleorganizations. The documents have been each designed specifically forthe targeted organization in both language and content.

The vulnerability could be a slight variation or may be covered bythe existing CVEs and we are awaiting confirmation from MicrosoftSecurity Response Center. Nevertheless, no patches appear to beavailable, so, as always, be careful opening unsolicited Word documents.

Update - Feb 1st, 2007 11:40 UTC: We have receivedconfirmation from Microsoft that the vulnerability being used in theseattacks is in...

Hon Lau | 25 Jan 2007 08:00:00 GMT | 0 comments

We’ve seen many threats using vulnerabilities based on MicrosoftOffice documents over the last year, so it’s no surprise that we haverecently observed new samples of a threat that follows the same theme.This threat named Trojan.Mdropper.W is using the new Microsoft Word 2000 Unspecified Code Execution Vulnerability (BID22225)to drop threats onto a compromised computer. When the infected Worddocument is opened, it uses an exploit to drop some files onto thecomputer. These files are back door Trojans that enable an attacker togain remote access to your computer.

This vulnerability comes on the back of three other recent and unpatched Microsoft Word vulnerabilities, which are:

BID21518...

Peter Ferrie | 24 Jan 2007 08:00:00 GMT | 0 comments

At AVAR 2006,I presented a paper which discussed ways in which virtual machines arevulnerable to detection and, in some cases, forced hangs or crashes.

The paper briefly discusses the two major types of virtual machines("hardware-bound" and "pure software") and the two hardware-boundsubtypes ("hardware-assisted" and "reduced-privilege guest"). The focusof the paper is the different ways in which various virtual machinescan be detected. There are detections for VMware, VirtualPC, Parallels,Bochs, Hydra (though the published methods have since been fixed),QEMU, Atlantis and Sandbox, along with lots of source code.

The slides from the talk are also available, but without thecommentary, they're not quite as interesting. The paper is availablefrom here. The slides are available from...

Matthew Conover | 22 Jan 2007 08:00:00 GMT | 0 comments

Continued from Part 1...

Exploiting double free vulnerabilities: Case 1

The first way that a double free vulnerability can be exploited is when the first free puts the chunk on the Lookaside (which the Windows heap implementation tries to use before the FreeList since it's more efficient). When a chunk is freed to the Lookaside, the Chunk is still marked as busy (that is, Chunk.Flags & BUSY_FLAG is set) to prevent the chunk from being coalesced with the previous/next chunk. That's because entries on the Lookasidelist are meant to be a fast allocate/deallocate (akin to "fast bins" inthe GLIBC and related Unix heap implementations). By contrast, entrieson the FreeList are frequentlycoalesced when a chunk is being freed and the chunk before/after it isalso free (to make larger contiguous chunks of memory available...

Matthew Conover | 19 Jan 2007 08:00:00 GMT | 0 comments

In light of the recent CSRSS double free bug, I wanted to providesome information on the exploitation of double frees on Windows on XPSP2 and later. Prior to XP SP2, double frees were trivial to exploit,but now the security cookie (in each heap chunk) and safe unlinkingchecks make it more difficult to exploit. So this blog entry willdiscuss the exploitability on XP SP2 and later heap implements.

Note: If you're not familiar with Windows heap terminology, pleasereview the slides from our CanSecWest 2004 heap presentation, archivedhere: http://www.cybertech.net/~sh0ksh0k/projects/winheap.

Oded Horovitz and I did not look into this topic much in ouroriginal presentation on Reliable Windows Heap Exploitation atCanSecWest 2004. Later that same year, I discussed how to defeat thesafe unlinking check at SyScan 2004, but I did not consider itsrelevance to double free...