(Pwn2Own) QNAP TS-453E server_handlers.pyc rr2s.kwargs Error Message Information Disclosure Vulnerability

March 30th, 2026
ZDI-26-242 ZDI-CAN-28426

CVE ID

CVE-2025-62840

CVSS Score

3.5 AV:A/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N

Affected Vendors

QNAP

Affected Products

TS-453E

Vulnerability Details

This vulnerability allows network-adjacent attackers to disclose sensitive information on affected installations of QNAP TS-453E devices. Although authentication is required to exploit this vulnerability, the existing authentication mechanism can be bypassed.

The specific flaw exists within the handling of the rr2s.kwargs parameter provided to the server_handlers.pyc endpoint. The issue results from outputting an error message that includes sensitive information. An attacker can leverage this in conjunction with other vulnerabilities to execute arbitrary code in the context of the RR2 administrator.

Additional Details

QNAP has issued an update to correct this vulnerability. More details can be found at:
https://www.qnap.com/en/security-advisory/qsa-25-46

Disclosure Timeline

  • 2025-11-18 - Vulnerability reported to vendor
  • 2026-03-30 - Coordinated public release of advisory
  • 2026-03-30 - Advisory Updated

Credit

Bongeun Koo (@kiddo_pwn) and Evangelos Daravigkas (@freddo_1337) of Team DDOS

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