Huge Vulnerability Spike at the End of the Year

Vanessa

Hey everyone, welcome back to 'It's all about Vulnerabilities.' I'm Vanessa, and as always, I'm joined by Alex and Daniel. December's Microsoft Patch Tuesday just dropped—so let's kick things off with the numbers. Alex, wanna start us off with how this month stacks up?

Alex

Absolutely. Microsoft patched 57 vulnerabilities this time, depending on which report you check, it might say 56 or 57, but let's stick with 57 because that's what BleepingComputer and others are listing. What's wild is that on Patch Tuesday itself, there were a total of 619 vulnerabilities published across all vendors—Microsoft just made up a slice of that pie. For perspective, the daily average in 2025 is about 130. That's a big spike, right?

Daniel

Indeed, that's a massive uptick for a single day. But if you look historically, this isn't just about numbers. In the 90s and early 2000s, patching was all about the core operating system, right? Now, the focus is shifting. We're seeing more vulnerabilities coming from cloud integrations, device drivers, and SaaS components rather than just Windows itself. It's a bigger, more complicated ecosystem than ever before.

Vanessa

Yeah, and it's not just the volume, it's the variety that really gets me. Of those 57 Microsoft CVEs, 28 were elevation of privilege, which is, like, pretty much half, right? And then 19 were remote code execution. The rest split up as four info disclosure, three denial of service, and two spoofing issues. It really puts the emphasis on how attackers are still going for initial access and privilege escalation via classic vectors.

Alex

And you know, it's not just Microsoft that's making things busy. With Oracle, Adobe, Fortinet, Google, all dropping big dumps on the same day, security and vulnerability teams are really feeling the pressure. Actually, this reminds me a bit of what we discussed in episode two—the patching cycles just keep accelerating, and everyone's got to move faster.

Daniel

Quite. And don't forget, that acceleration isn't evenly matched with resources or capabilities, especially as more of the attack surface now lives far from the traditional enterprise perimeter thanks to SaaS and cloud services. So, the real challenge now is not just patching quickly, it's knowing what matters most—what to patch, when, and where your blind spots are hiding.

Vanessa

Knowing what matters is the real trick. Speaking of, some of what mattered most this month were zero-days and critical vulnerabilities that got fixed. Should we get into those?

Alex

Yeah, let's talk zero-days. This Patch Tuesday addressed three zero-day vulnerabilities, including one that was actively being exploited. The most concerning was CVE-2025-62221—that's the Windows Cloud Files Mini Filter Driver flaw. If exploited, it lets an authenticated attacker get SYSTEM privileges locally. Microsoft says this was already exploited in the wild, which is as serious as it gets.

Daniel

And by the way, for context, Microsoft tends to label a vulnerability a zero-day if it's either been publicly disclosed or actively exploited before a patch is available. In this case, both criteria were met—quite a feat. With SYSTEM access, an attacker can basically do anything on the box. That’s always one to patch ASAP.

Vanessa

Totally. The other two zero-days patched were both pretty fascinating as well. One’s in PowerShell, which we’ll get to next chapter, but that third one—CVE-2025-64671—is in the GitHub Copilot plugin for JetBrains IDEs. But before we move off criticals, can we mention those Microsoft Office remote code execution bugs? CVE-2025-62554 and 62557, both rated critical. They can be exploited through social engineering, and what’s really gnarly is that attackers don’t even need you to open the file—just the Preview Pane can be enough. That’s big for phishing, isn’t it?

Alex

That's the scary bit. You get an email, you use Preview Pane because you think it's safe, and—bam—RCE. Microsoft did flag these as “less likely” to be exploited, but honestly, we all know that's just hedging. We've seen enough clever phishing kits to know attackers will work around so-called safe defaults.

Vanessa

Yeah, and actually, I had this internal phishing engagement recently—can't share details, obviously—but it was this kind of bug, an unpatched Office RCE, that could've let us move laterally around their network without anyone noticing. People underestimate how quickly those docs get opened, or previewed, I should say. It's a huge risk. So if any listeners still haven’t patched Office, please get on it!

Daniel

It's a classic lesson, really: exploit chains remain fundamentally the same, but the delivery vehicles just keep evolving. Preview Panes were a “safe” productivity hack once—but now, they're an attack vector. Interesting how these patterns repeat, just with new tools.

Alex

Well said, Daniel. Shall we dig into PowerShell next? That's a whole world of pain by itself this month.

Vanessa

Absolutely. So, PowerShell had its own remote code execution zero-day this round—CVE-2025-54100. This is all about how Invoke-WebRequest handles remote web content. If you—well, not you, but an attacker—crafts a webpage with embedded scripts and someone uses Invoke-WebRequest to fetch it, that script could get executed locally. Microsoft added a new warning now, so users get prompted before code runs, unless you use the -UseBasicParsing option. So, that's something, but it's still a pretty risky behavior by default.

Alex

It's actually kind of wild that we're still vulnerable to command injection through such trusted tools. Researchers like DeadOverflow and Justin Necke have been publishing about this for years now, but the fact that a single switch can decide whether or not you're potentially exposed... It shows how easy it is to overlook these things in real-world automation. It's not even that niche. A lot of defenders still parse web content in their scheduled tasks—sometimes they don't even realize they're allowing arbitrary code in that pipeline.

Vanessa

Yeah, spot on. In phishing and social engineering engagements, I keep seeing PowerShell used as the payload delivery vehicle. Because it's everywhere, and—I'll be honest—if you can get something from the web onto a desktop, and it gets run with even user-level privileges, you’re off to a great start as an attacker. Automation scripts, post-exploitation frameworks—they all rely on tools like PowerShell. Most people don't second-guess how trustworthy some random downloaded content might be until it's way too late.

Daniel

Precisely. It's the ubiquity of PowerShell that's frightening. Automation, default installation, and the sheer depth of functionality make command injection incredibly attractive for malicious actors. And the “user-facing warning” is a start, but honestly, how many users just click 'Yes' or add whatever flag is suggested to get rid of the pop-up? Defensive measures are only as strong as their actual adoption and user-awareness levels, unfortunately.

Alex

We keep coming back to this idea: familiar tools become attack surfaces. I mean, where was I going with this... Oh right, if you’re building tooling or automation, always assume content from the web can be hostile—even if you trust the source, transit can be compromised. I can't stress enough: review what privileges your automation scripts run with. Least privilege, always.

Vanessa

I like that—“assume web content is hostile.” That’s exactly what attackers are doing, and that's what we, as defenders or testers, should do too. Okay, we’ve danced around it enough—let’s dig into cloud, AI, and dev tool vulnerabilities, because that’s where stuff is getting spicy lately.

Daniel

Indeed, this month's most intriguing fix, at least for me, was the GitHub Copilot for JetBrains IDEs vulnerability—CVE-2025-64671, or as security researcher Ari Marzuk calls it, “IDEsaster.” Essentially, if someone dropped a malicious Cross Prompt Injection into an untrusted file, Copilot could end up running arbitrary commands locally, especially if the auto-approve terminal setting was on. It's a sobering reminder that AI-powered tools can introduce new classes of risk to the developer supply chain.

Alex

Yeah, prompt injection's really getting out of hand! It's not limited to chatbots anymore—now it's in code editors, too. Ari Marzuk's research tracked how those prompts, embedded in untrusted files, could totally hijack developer workflows. In the early 2000s, we were worried about malformed config files or corrupted settings causing denial of service or privilege issues. That was relatively simple—you had control over most inputs. But with AI plugins fetching suggestions from the cloud and integrating them directly into the dev environment, you're multiplying your attack surface. A simple code completion gone rogue, and your dev machine's running whatever the attacker wants.

Vanessa

Honestly, it's terrifying and fascinating at the same time. With AI in the toolchain, there's this false sense of security—like, if it's Copilot or whatever, people trust it more than some dodgy GitHub repo. But as we’re seeing, it's actually just another place to inject malicious content. Supply chain risk moves upstream, into code suggestions, into the very plugins people use to work faster. All of it becomes a potential entry point. We really do have to treat every layer as potentially compromised these days.

Daniel

Absolutely, and given how many organizations are standardizing on these IDEs and AI plugins, the scale of risk is huge. What’s striking is the convergence of SaaS, cloud services, and AI—each integration point is another vector. It’s as if every new bit of developer convenience comes with a hidden asterisk: “may be hijacked at any moment, patch often.”

Alex

If you’d told me twenty years ago we’d be worrying about chatbots and machine-generated code running amok, I’d have laughed! I always mix this up, was it 2002 or 2003 when that first big config file bug happened in a major IDE? Anyway, the point is, we used to think the old threats would go away as tooling improved. Instead, same risks, just better automation for the bad guys. Now with AI—and I’m not trying to scare people, but—prompt hygiene is the new password hygiene.

Vanessa

So true. I guess that brings us to the broader debate: if a vulnerability is only triggered by a malicious config file or dodgy plugin, is it a “real” vulnerability? Or is that just on the user or admin? It’s turning into a real grey area, isn’t it?

Alex

Yeah, let’s dig deeper into this config file thing. There’s been a lot of debate—some say if you need a malicious config file to trigger a bug, it shouldn't count as a “real” vulnerability. But I totally disagree. Config files aren’t always carefully curated—they’re downloaded, copied, shared, or generated by other tools or, these days, by LLMs that can hallucinate mistakes or backdoors. Trusting those blindly is just asking for trouble. Honestly, if you’re running a tool as root, but some admin or process can drop arbitrary files that lead to code exec, that’s a privilege escalation—real world, real risk.

Daniel

Yes, and consider the implication in automated toolchains. A lot of tools rely on exit codes to determine what happens next, but even a simple crash caused by a bad config can have unintended side effects. Some will argue you shouldn’t trust return codes for anything security-relevant, but then—why bother with them at all? Defensive programming is crucial, but pushing the responsibility to someone else doesn’t eliminate the risk—it just shifts the blame. Risk awareness, not trust, is what matters here.

Vanessa

That’s the thing—even a low-severity bug caused by a config edge case can still matter in a pentest, especially if it lets you break the workflow, escalate privileges, or just crash something business-critical. I’ve seen devs argue “but nobody would use a config like that,” and I’m like, you have no idea what people will try in production. Tools pulling configs from public places, or from dodgy documentation, just amplifies the risk.

Alex

Totally. And on that note, quick story—from a pen test a while back, we found a weak config file that the dev team swore was “benign.” Turns out, it let us escalate privileges by chaining together a few overlooked interactions. They were stunned. So yes, config-based bugs are real-world issues, not just theoretical “you shouldn’t do that” scenarios.

Daniel

So, whether it's config files, malformed prompts, or trusted plugins, the takeaway here is to build defenses that assume mistakes, not perfection. The more we rely on automation and integration, the more important it is to not trust blindly, and to ask tough questions about how we code, test, and deploy.

Vanessa

Couldn’t agree more. All right, on that slightly philosophical note, I reckon we should wrap for today. This Patch Tuesday was a wild ride—zero-days, PowerShell headaches, AI in the crosshairs, and eternal config paranoia. Thanks for listening, everyone—patch early, patch often, and be skeptical about what you trust!

Alex

And thanks for joining us. Watch out for those next big rounds of vulnerabilities—we’ll be breaking them down each month. See you all soon!

Daniel

Indeed. Until next time—stay vigilant, keep questioning, and goodbye from me.

Vanessa

Bye Alex, bye Daniel! Catch you both for the next episode. And thanks everyone for tuning in. Enjoy your holidays and see you next year!