Leaving The Front Door Open (Part 1 of 5)

In simpler times, cybersecurity was all about repelling external attacks and keeping threats outside the perimeter. Firewalls, antivirus software, and intrusion detection systems were built for this. But in today’s identity-first world, the threat model has gotten more complicated and difficult to detect. Attackers aren’t brute-forcing their way in anymore — they’re logging in —  which circumvents many of these solutions.

With the rise of credential-based attacks, session hijacking, and phishing, cybercriminals are bypassing traditional perimeter defenses and gaining access by exploiting the weakest link: identity. Once a user is authenticated and issued a session, most security controls assume everything is fine. But increasingly, it's that initial login — that token — that's being compromised and then abused.

The Identity Attack Surface

Today, nearly every enterprise service is accessible via SSO, VPN, or a federated identity system. And while these systems can provide a relatively seamless user experience, they also create a single point of failure. If an attacker compromises your identity provider, they can often move freely within your environment, undetected.

Common identity-based attack vectors include:

• Credential stuffing: using leaked username/password combos from breaches
• Phishing and MFA fatigue: tricking users into granting access
• Token replay and session hijacking: abusing valid tokens to impersonate users

In each case, the attacker doesn’t need to bypass endpoint defenses or exploit a vulnerability. They just need to look legitimate long enough to be trusted and inflict damage.

The Illusion of Security

Traditional identity systems are built around binary decisions: allow or deny access. But trust isn’t binary — it’s contextual. A login from a known device during business hours might be fine on one day, but highly suspicious on another. Without continuous risk evaluation, identity platforms can’t distinguish between a real user and an adversary using valid credentials.

Once the attacker is in, most identity systems check out. There’s no visibility into what the user does post-authentication, and no mechanisms to revoke access based on behavior.

Why It Matters

The implications are huge. A compromised identity can:

• Serve as a launch point for lateral movement
• Access sensitive data and exfiltrate it without triggering alerts
• Evade detection by appearing legitimate to EDR and SIEM tools

As more organizations adopt Zero Trust and distributed architectures, identity is becoming the new perimeter. But without the ability to detect misuse in real time, that perimeter is paper-thin.

What's Next

In the next article, we’ll explore what attackers do after the login — how they "live off the land" and exploit native tools to move laterally, avoid detection, and ultimately achieve their objectives. We'll also examine why Endpoint Detection and Response (EDR) alone can't keep up, and why the gap between identity and endpoint is putting organizations at risk.

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This the 1st article in a 5-part series.

Read: Part 1 | Part 2 | Part 3 | Part 4 | Part 5

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