Access Control Vulnerabilities

When working with access control vulnerabilities, flaws that let unauthorized users gain rights they shouldn't have. Also known as ACL bugs, they are the weak links that let attackers walk into systems, steal funds, or tamper with data. In the crypto world, a broken access check can mean losing tokens on an exchange, exposing user wallets, or letting a rogue admin drain a smart contract. Understanding these flaws helps you spot red flags before they turn into costly incidents.

Typical Attack Paths and How They Chain Together

One common path is privilege escalation, the process where a low‑level user tricks the system into granting higher rights. Attackers often start with a simple flaw—maybe an API endpoint that doesn’t verify the caller’s role—and then climb up to admin privileges. This escalation is amplified when the least‑privilege principle, the practice of giving users only the access they absolutely need is ignored. In many crypto exchange reviews, you’ll see auditors flag missing role checks as a red flag because they open the door for privilege escalation. Another frequent issue is insecure direct object references (IDOR), where an attacker changes a resource identifier to access data they shouldn’t. Combine an IDOR with a privilege‑escalation bug, and you can move funds across accounts with a few crafted URLs.

Another hot ticket is authentication bypass, techniques that let a user skip login checks entirely. Badly implemented token validation, predictable session IDs, or missing multi‑factor enforcement are classic entry points. Crypto platforms that skip proper authentication often appear in exchange reviews as high‑risk venues. Once an attacker is inside, they can exploit other access control gaps to broaden their reach. For example, a trader might use a bypass to submit a withdrawal request that the system treats as coming from a verified user, leading straight to fund loss. The chain reaction—authentication bypass + missing role checks + IDOR—creates a perfect storm for a security breach.

Defending against these issues starts with a solid role‑based access control (RBAC), a system that assigns permissions based on user roles and enforces them at every entry point. When RBAC is enforced, even if an attacker finds a way to bypass authentication, they still hit a wall unless they also manage to spoof a high‑level role. Pair RBAC with strict input validation, regular permission audits, and automated testing, and you cut the attack surface dramatically. In practice, many of the exchange reviews we cover highlight platforms that adopt RBAC and regularly rotate keys as more trustworthy. Applying these controls, along with continuous monitoring for suspicious privilege changes, gives you a realistic defense against the common access control vulnerabilities that plague the crypto ecosystem.

Below you’ll find a curated set of articles that dig into real‑world examples, mitigation strategies, and how the latest crypto platforms handle—or mishandle—these security challenges. Dive in to see the details, learn practical steps, and keep your assets safe.