Most serious vulnerabilities don't start as critical. They become critical through privilege escalation.
As a bug bounty hunter, I've learned this the hard way — low-severity issues often hide the most dangerous outcomes.
Let's talk about why privilege escalation matters, and the 12 common chains that repeatedly lead to full takeover in real-world programs.
🔑 What Privilege Escalation Really Means (In Practice)
Privilege escalation isn't magic.
It's simply:
Doing more than you're supposed to — step by step.
Most platforms have:
- Users
- Moderators
- Admins
- Internal systems
The moment boundaries blur, escalation begins.
🧠 Why Bug Bounty Hunters Love Escalation Bugs
Because escalation bugs:
- Are harder to detect automatically
- Bypass traditional scanners
- Expose real business impact
- Often lead to chainable exploits
Companies don't fear XSS alone. They fear what XSS becomes.
🔗 12 Privilege Escalation Chains That Lead to Full Takeover
These are educational patterns, not instructions — used daily by defenders and ethical researchers.
1️⃣ IDOR → Profile Edit → Account Takeover
A simple object reference issue can allow:
- Editing another user's profile
- Changing email or recovery settings
- Hijacking the account silently
Low effort. High impact.
2️⃣ Broken Access Control → Admin API Exposure
Missing role checks in backend APIs often allow:
- User-level tokens accessing admin routes
- Privilege jumps without UI access
APIs don't care who you are — only what you're allowed to do.
3️⃣ File Upload → Path Traversal → Config Leak
An innocent upload feature can:
- Expose sensitive configs
- Reveal tokens or credentials
- Lead to internal access
Most escalations start with files.
4️⃣ OAuth Misbinding → Cross-Account Login
Improper OAuth validation can allow:
- Logging into another user's account
- Session confusion across identities
SSO convenience comes with hidden risks.
5️⃣ Password Reset Logic Flaws → Full Control
Common mistakes:
- Predictable tokens
- Missing rate limits
- Email verification bypasses
Reset flows are escalation goldmines.
6️⃣ Stored XSS → Admin Session Hijack
A harmless-looking input:
- Executes when an admin views it
- Steals session tokens
- Grants elevated access
Context is everything.
7️⃣ Weak Role Separation → Horizontal to Vertical Escalation
When roles aren't clearly enforced:
- Moderators act as admins
- Users perform staff actions
Assumed trust becomes exploited trust.
8️⃣ Business Logic Abuse → Privileged Actions
No vulnerability scanner catches this.
Examples:
- Self-approval flows
- Missing state checks
- Action replay attacks
This is where humans beat tools.
9️⃣ JWT Manipulation → Role Forgery
Misconfigured JWTs can allow:
- Role tampering
- Token reuse
- Privilege injection
Tokens are only as strong as their validation.
🔟 Debug Endpoints → Internal Access
Leftover debug features often expose:
- Admin panels
- Logs
- Internal logic
"Temporary" endpoints rarely stay temporary.
1️⃣1️⃣ CSRF → Privileged Action Abuse
If privileged actions lack protection:
- Admins can be tricked
- Settings silently changed
- Accounts compromised indirectly
Victims don't even know it happened.
1️⃣2️⃣ Low-Severity Bug → Chained Takeover
This is the real lesson.
One bug rarely kills a system. Chains do.
🛡️ Defensive Takeaways (From a Bug Hunter's View)
If you're defending systems:
- Test roles aggressively
- Validate every privilege boundary
- Think like an attacker — but act responsibly
- Assume features will be chained
Security fails in the connections, not the code.
🌱 Final Thought
Privilege escalation isn't a vulnerability class.
It's a mindset.
As a bug bounty hunter, I don't hunt for "critical bugs." I hunt for paths.
And most paths lead upward. 🔓
💬 Your Turn
What's the most unexpected escalation chain you've seen — or prevented?
👏 If this helped you, clap, comment, and follow for more real-world bug bounty and security insights.