After a week away recovering from too much turkey and sweet potato casserole, we’re back for more security news! And if you need something to shake you out of that turkey-induced coma, React Server has a single request Remote Code Execution flaw in versions 19.0.1, 19.1.2, and 19.2.1.

The issue is insecure deserialization in the Flight protocol, as implemented right in React Server, and notably also used in Next.js. Those two organizations have both issued Security Advisories for CVSS 10.0 CVEs.

There are reports of a public Proof of Concept (PoC), but the repository that has been linked explicitly calls out that it is not a true PoC, but merely research into how the vulnerability might work. As far as I can tell, there is not yet a public PoC, but reputable researchers have been able to reverse engineer the problem. This implies that mass exploitation attempts are not far off, if they haven’t already started.

Legal AI Breaks Attorney-Client Privilege

We often cover security flaws that are discovered by merely poking around the source of a web interface. [Alex Schapiro] went above and beyond the call of duty, manually looking through minified JS, to discover a major data leak in the Filevine legal AI. And the best part, the problem isn’t even in the AI agent this time.

The story starts with subdomain enumeration — the process of searching DNS records, Google results, and other sources for valid subdomains. That resulted in a valid subdomain and a not-quite-valid web endpoint. This is where [Alex] started digging though Javascript, and found an Amazon AWS endpoint, and a reference to BOX_SERVICE. Making requests against the listed endpoint resulted in both boxFolders and a boxToken in the response. What are those, and what is Box?

Box is a file sharing system, similar to a Google Drive or even Microsoft Sharepoint. And that boxToken was a valid admin-level token for a real law firm, containing plenty of confidential records. It was at this point that [Alex] stopped interacting with the Filevine endpoints, and contacted their security team. There was a reasonably quick turnaround, and when [Alex] re-tested the flaw a month later, it had been fixed.

JSON Formatting As A Service

The web is full of useful tools, and I’m sure we all use them from time to time. Or maybe I’m the only lazy one that types a math problem into Google instead of opening a dedicated calculator program. I’m also guilty of pasting base64 data into a conversion web site instead of just piping it through base64 and xxd in the terminal. Watchtowr researchers are apparently familiar with such laziness efficiency, in the form of JSONformatter and CodeBeautify. Those two tools have an interesting feature: an online save function.

You may see where this is going. Many of us use Github Gists, which supports secret gists protected by long, random URLs. JSONformatter and CodeBeautify don’t. Those URLs are short enough to enumerate — not to mention there is a Recent Links page on both sites. Between the two sites, there are over 80,000 saved JSON snippets. What could possibly go wrong? Not all of that JSON was intended to be public. It’s not hard to predict that JSON containing secrets were leaked through these sites.

And then on to the big question: Is anybody watching? Watchtowr researchers beautified a JSON containing a Canarytoken in the form of AWS credentials. The JSON was saved with the 24 hour timeout, and 48 hours later, the Canarytoken was triggered. That means that someone is watching and collecting those JSON snippets, and looking for secrets. The moral? Don’t upload your passwords to public sites.

Shai Hulud Rises Again

NPM continues to be a bit of a security train wreck, with the Shai Hulud worm making another appearance, with some upgraded smarts. This time around, the automated worm managed to infect 754 packages. It comes with a new trick: pushing the pilfered secrets directly to GitHub repositories, to overcome the rate limiting that effected this worm the first time around. There were over 33,000 unique credentials captured in this wave. When researchers at GitGuardian tested that list a couple days later, about 10% were still valid.

This wave was launched by a PostHog credential that allowed a malicious update to the PostHog NPM package. The nature of Node.js means that this worm was able to very quickly spread through packages where maintainers were using that package. Version 2.0 of Shai Hulud also includes another nasty surprise, in the form of a remote control mechanism stealthily installed on compromised machines. It implies that this is not the last time we’ll see Shai Hulud causing problems.

Bits and Bytes

[Vortex] at ByteRay took a look at an industrial cellular router, and found a couple major issues. This ALLNET router has an RCE, due to CGI handling of unauthenticated HTTP requests. It’s literally just /cgi-bin/popen.cgi?command=whoami to run code as root. That’s not the only issue here, as there’s also a hardcoded username and password. [Vortex] was able to derive that backdoor account information and use hashcat to crack the password. I was unable to confirm whether patched firmware is available.

Google is tired of their users getting scammed by spam phone calls and texts. Their latest salvo in trying to defeat such scams is in-call scam protection. This essentially detects a banking app that is opened as a result of a phone call. When this scenario is detected, a warning dialogue is presented, that suggests the user hangs up the call, and forces a 30 second waiting period. While this may sound terrible for sophisticated users, it is likely to help prevent fraud against our collective parents and grandparents.

What seemed to be just an illegal gambling ring of web sites, now seems to be the front for an Advanced Persistent Threat (APT). That term, btw, usually refers to a government-sponsored hacking effort. In this case, instead of a gambling fraud targeting Indonesians, it appears to be targeting Western infrastructure. One of the strongest arguments for this claim is the fact that this network has been operating for over 14 years, and includes a mind-boggling 328,000 domains. Quite the odd one.