Cookie manipulation (stored DOM-based)
Summary: PortSwigger describes DOM-based cookie manipulation as a stored DOM-based vulnerability where a script writes controllable data into a cookie's value, letting an attacker construct a URL that sets an arbitrary value in another user's cookie when visited. The impact depends on the cookie's role: a setting such as production versus demo mode can lead the user to perform unintended actions, while a session cookie can enable session fixation using a valid token the attacker obtained from the application.
Key Takeaway: A cookie that controls privileged actions or user sessions is the difference between a nuisance and a session fixation attack, and PortSwigger notes Burp's static analysis can flag issues that are not actually exploitable, so a finding without dynamic evidence still needs code and execution-path review.
Read the original at PortSwigger Research ↗
- Topics
- Vulnerabilities & Patching
- Related
- Attackers Exploit UnrealIRCd Flaw That Enables Server-Level Command Injection Cyber Risks · Nov 14, 2026U.S. CISA adds Check Point and UnrealIRCd flaws to its Known Exploited Vulnerabilities catalog Cyber Risks · Nov 14, 2026PostgreSQL Patches 52 Flaws, Including 22-Year-Old Bug Enabling Authenticated RCE Cyber Risks · Nov 13, 2026