The suddenly popular videoconferencing app Zoom has issued a patch for a vulnerability in its Windows client that allowed attackers to steal the user's Windows login credentials from malicious chat links.
Hi @zoom_us & @NCSC – here is an example of exploiting the Zoom Windows client using UNC path injection to expose credentials for use in SMBRelay attacks. The screen shot below shows an example UNC path link and the credentials being exposed (redacted). pic.twitter.com/gjWXas7TMO
— Hacker Fantastic (@hackerfantastic) March 31, 2020
I made a simple demo of the latest Zoom UNC Path Injection Vulnerability, Take care and don't click on ANY UNC Path hyperlinks!
P.S. I used putty as a payload.exe which could be ANY_THING_ELSE.exe
— Mohamed A. Baset (@SymbianSyMoh) April 1, 2020
"Zoom issued a fix for this and other bugs, promising better transparency going forward," reports Mark Hachman at PCWorld:
An unpatched vulnerability within Zoom allows an attacker to drop a malicious link into a chat window and use it to steal a Windows password, according to reports.
A hacker could use an attack called a UNC path injection to expose credentials, according to an attack posted on Twitter and subsequently followed up with an additional video. According to The Hacker News, that's because Windows exposes a user's login name and password to a remote server when attempting to connect to it and download a file.
Update: After this story and others went live April 1, Zoom CEO Eric Yuan addressed Zoom security and other issues in a blog post. Part of the blog post detailed a bug fix to be released, which would fix the UNC vulnerability described in our original story, among other things. The fix appears to be pushing out automatically to users. PCWorld staff who've already received the fix report the version number as 4.6.9 (19253.0401).
READ MORE at pcworld.com:
We appreciate the scrutiny and questions we have been getting – about how the service works, about our infrastructure and capacity, and about our privacy and security policies. These are the questions that will make Zoom better [Blog Post] https://t.co/tDcWxRIF2V by @ericsyuan
— Zoom (@zoom_us) April 2, 2020
Well, if every societal institution had performed as well as Zoom's infrastructure team, we'd be OK. https://t.co/CKo4h6LZ5k
— Antonio García Martínez (@antoniogm) April 3, 2020
I have more years of experience in engineering than i like to mention.
But this does not compute for me…
Keeping the infrastructure in check for a 20x on that scale is insanely impressive.
Hats off to the zoom eng + infrastructure team. https://t.co/a9qFm3EOeC
— Andreas Klinger ✌️ (@andreasklinger) April 3, 2020
— Remi Afon (@RemiAfon) April 1, 2020
Attention Zoom users! A vulnerability has been identified that could allow an attacker to gain control of a system or collect your Windows credentials.
— U of G IT (@uofgccs) April 2, 2020