## Summary
D-Link DIR-513 v1.10 contains a stack buffer overflow in the web interface endpoint POST /goform/formEasySetupWizard when the curtime parameter is supplied with an overly long value. The issue is described as CWE-121 and is rated critical (CVSS 9.8).
## Technical Details
- Vulnerable component: web form handler goform/formEasySetupWizard.
- Trigger: curtime parameter passed in the request body to POST /goform/formEasySetupWizard.
- Root condition (as evidenced by reference PoC request): sending a very large curtime value (long numeric string) in application/x-www-form-urlencoded content.
- Example request structure from reference:
- Endpoint: /goform/formEasySetupWizard
- Method: POST
- Body parameter: curtime=<very long string>
- The reference material does not include exploit code, but it demonstrates the methodology of crafting an HTTP request with an oversized curtime field.
## Affected
- D-Link DIR-513 firmware v1.10
## Impact
- Stack buffer overflow can lead to memory corruption with potential remote compromise.
- CVSS indicates high impact on confidentiality, integrity, and availability (C/H, I/H, A/H) with no privileges required (PR:N) and no user interaction (UI:N).
## Mitigation
1. Check D-Link’s security bulletin page for the DIR-513 advisory and apply the vendor-recommended upgrade/fix for the affected firmware.
2. If an upgrade is not immediately available, restrict access to the router’s web management interface (e.g., limit exposure to trusted networks only) to reduce the likelihood of reaching POST /goform/formEasySetupWizard.
3. Monitor for anomalous requests to POST /goform/formEasySetupWizard containing unusually long curtime values.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CWE-121