This is a summary of the AI-generated 10-question deep analysis. The full version (longer answers, follow-up Q&A, related CVEs) requires login. Read the full analysis β
Q1What is this vulnerability? (Essence + Consequences)
π¨ **Essence**: A flaw in Symfony's HttpKernel `FragmentListener`. π **Consequences**: Remote attackers bypass URL signing and security rules.β¦
π‘οΈ **Root Cause**: Missing check for the `_controller` attribute. π **Flaw**: The code fails to validate if `_controller` is set during ESI/SSI processing.β¦
π¦ **Component**: Sensio Labs Symfony HttpKernel. π **Affected Versions**: 2.3.19-2.3.28, 2.4.9-2.4.10, 2.5.4-2.5.11, 2.6.0-2.6.7. βοΈ **Condition**: ESI or SSI support must be enabled.
Q4What can hackers do? (Privileges/Data)
π΅οΈ **Action**: Bypass URL signing mechanisms. π **Privileges**: Gain unauthorized access to protected resources. π **Data**: Potential exposure of internal logic or data by including invalid/no hash in requests.
Q5Is exploitation threshold high? (Auth/Config)
π **Threshold**: Low. π **Auth**: Remote attackers can exploit it without authentication. βοΈ **Config**: Only requires ESI/SSI to be enabled. No complex setup needed.
Q6Is there a public Exp? (PoC/Wild Exploitation)
π **PoC**: Yes. π§ͺ **Source**: Nuclei templates available on GitHub. π₯ **Status**: Publicly documented exploit logic exists for testing.
Q7How to self-check? (Features/Scanning)
π **Check**: Scan for `/_fragment` endpoint. π‘ **Feature**: Verify if ESI/SSI is enabled in Symfony config. π οΈ **Tool**: Use Nuclei or similar scanners targeting CVE-2015-4050.
Q8Is it fixed officially? (Patch/Mitigation)
β **Fixed**: Yes. π’ **Source**: Official Symfony blog confirmed the fix. π¦ **Action**: Upgrade to patched versions or apply vendor advisories (e.g., Fedora packages).
Q9What if no patch? (Workaround)
π§ **Workaround**: Disable ESI/SSI support if not strictly needed. π« **Mitigation**: Ensure `_controller` is always set manually in custom implementations. π **Block**: Restrict access to `/_fragment` via WAF rules.
Q10Is it urgent? (Priority Suggestion)
π₯ **Priority**: High. π¨ **Urgency**: Critical for affected versions with ESI/SSI enabled. β³ **Action**: Patch immediately to prevent unauthorized access bypasses.