Contact UsWDN News & more...

Another severe flaw in Signal desktop app lets hackers steal your chats in plaintext


For the second time in no longer up to per week, users of the usual fracture-to-fracture encrypted Signal messaging app fetch to update their desktop applications once extra to patch yet another severe code injection vulnerability.

Chanced on Monday by the identical body of workers of safety researchers, the newly found vulnerability poses the identical risk because the outdated one, allowing distant attackers to inject malicious code on the recipients’ Signal desktop app appropriate kind by sending them a message—without requiring somebody interplay.

To designate extra about the vital code injection vulnerability (CVE-2018-10994), you might well per chance per chance be taught our outdated article overlaying how researchers win the Signal flaw and the procedure it works.

The very best distinction between the two is that the outdated flaw resides within the feature that handles links shared within the chat, whereas the brand new vulnerability (CVE-2018-11101) exists in a obvious feature that handles the validation of quoted messages, i.e., quoting a outdated message in a respond.


In varied words, to cash in on of the newly patched malicious program on weak variations of Signal desktop app, all an attacker wants to fabricate is send a malicious HTML/javascript code as a message to the sufferer, and then quote/respond to that identical message with any random text.

If the sufferer receives this quoted message containing the malicious payload on its weak Signal desktop app, this also can automatically discontinue the payload, without requiring somebody interplay.

Exploiting Signal Code Injection to Get rid of Plaintext Chats

Till now the proof-of-principle payloads ragged to prove code injection vulnerabilities in Signal were restricted to embedding an HTML iFrame, or image/video/audio tags onto the sufferer’s desktop app.

Then again, researchers fetch now managed to craft a new PoC exploit that also can allow distant attackers to successfully plan shut all Signal conversations of the victims within the plaintext appropriate kind by sending them a message.

This hack literally defeats the explanation of an fracture-to-fracture encrypted messaging app, allowing distant attackers to without say acquire the take care of on users’ undeniable-text conversations without breaking the encryption.

Attackers Could per chance per chance per chance Presumably Get rid of Windows Password As Well

What’s worse?

Of their blog post, the researchers moreover indicated that an attacker also can even comprise recordsdata from a distant SMB share utilizing an HTML iFrame, that would moreover be abused to plan shut NTLMv2 hashed password for Windows users.

“In the Windows operative design, the CSP fails to prevent distant inclusion of property by strategy of the SMB protocol. In this case, distant execution of JavaScript also can moreover be finished by referencing the script in an SMB share because the source of an iframe label, as an instance: