WinRAR Attacks and Zero-Days: Why January's Security Headlines Should Worry Us All

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WinRAR Attacks and Zero-Days: Why January’s Security Headlines Should Worry Us All

If you’ve been following security news this past week, you’ve probably noticed a particularly unsettling pattern. We’re seeing active exploitation across multiple critical vulnerabilities, from widely-used compression tools to enterprise SSO systems. What’s especially concerning is how these attacks are targeting both legacy systems we’ve forgotten about and modern infrastructure we depend on daily.

The WinRAR Problem That Won’t Go Away

Let’s start with the elephant in the room. Google’s Threat Analysis Group just confirmed that multiple nation-state actors and cybercriminal groups are actively exploiting CVE-2025-8088, a critical vulnerability in WinRAR that was patched back in July 2025.

Here’s what bothers me about this: we’re six months past the patch release, and threat actors linked to Russia and China are still finding plenty of unpatched systems to compromise. WinRAR has over 500 million users worldwide, and clearly a significant portion haven’t updated. The attackers are using this as their initial access vector to deploy everything from ransomware to espionage tools.

This isn’t just about individual users either. I’ve seen WinRAR installed on corporate workstations more times than I can count, often forgotten about until something like this happens. If your organization uses WinRAR anywhere, now would be a good time to audit those installations.

Enterprise SSO Under Attack

Speaking of active exploitation, Fortinet just disclosed something that should make every enterprise security team nervous. They’ve confirmed that CVE-2026-24858, a critical FortiCloud SSO authentication bypass vulnerability, is being actively exploited in the wild.

What’s interesting here is Fortinet’s response. Rather than rush out a potentially flawed patch, they’ve temporarily blocked FortiCloud SSO connections from devices running vulnerable firmware versions. It’s a bold move that prioritizes security over convenience, and honestly, I respect that approach. Too often we see vendors push out hasty patches that create new problems.

But this does highlight a broader issue with SSO systems. When they fail, they fail catastrophically. A bypass vulnerability in your SSO solution essentially hands attackers the keys to your entire environment.

The Forgotten Attack Surface Problem

While we’re dealing with modern SSO bypasses, we also can’t ignore the legacy systems that continue to haunt our networks. A new critical Telnet server vulnerability serves as a stark reminder that “obsolete” doesn’t mean “gone.”

Hundreds of thousands of legacy systems and IoT devices still rely on Telnet for remote access. These aren’t systems that organizations actively maintain or even remember they have. They’re the industrial control systems, network appliances, and embedded devices that just keep running in the background until something like this forces us to pay attention.

The challenge here isn’t just patching – it’s discovery. How do you patch systems you don’t know exist? This is where asset inventory becomes critical, but I know how difficult that can be in practice, especially in environments that have grown organically over decades.

OpenSSL’s Dozen Vulnerabilities

On a slightly more positive note, OpenSSL just patched 12 vulnerabilities, including a high-severity remote code execution flaw. What’s remarkable here is that all 12 vulnerabilities were discovered by a single cybersecurity firm, which speaks to the value of dedicated security research.

OpenSSL is everywhere – it’s the cryptographic foundation for countless applications and services. The fact that we’re still finding RCE vulnerabilities in such a widely-used library is both concerning and expected. It’s concerning because of the potential impact, but expected because OpenSSL is under constant scrutiny by both security researchers and attackers.

The Bigger Picture

Looking at these incidents together, I see three trends that should inform our security strategies:

First, patch management remains our biggest challenge. The WinRAR situation shows that even when patches are available, getting them deployed consistently across an organization is still incredibly difficult.

Second, our attack surface is more complex than we often acknowledge. We’re simultaneously defending modern cloud SSO systems and decades-old Telnet implementations. That’s a lot of ground to cover, and it requires different approaches and expertise.

Third, the threat landscape is increasingly opportunistic. These aren’t targeted attacks against specific organizations – they’re mass exploitation campaigns that will hit anyone running vulnerable software. That makes proactive patching and asset management even more critical.

Looking Forward

If there’s one thing I’d recommend based on this week’s news, it’s conducting an honest assessment of your organization’s forgotten systems. Those Telnet-enabled devices, that WinRAR installation on the CFO’s laptop, the legacy applications that “just work” – these are the systems that will bite you.

We also need to get better at treating SSO systems as the critical infrastructure they are. When your SSO fails, everything fails. That means not just keeping it patched, but having monitoring, backup authentication methods, and incident response plans specific to SSO compromise.

The security community has made incredible progress over the past decade, but weeks like this remind us how much work we still have ahead of us.

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