Information Disclosure Vulnerability (CVE‑2025‑62840) in QNAP TS‑453E NAS Risks Sensitive Data Exposure

Information Disclosure Vulnerability (CVE‑2025‑62840) in QNAP TS‑453E NAS Risks Sensitive Data Exposure

What It Is – A low‑to‑moderate severity flaw (CVSS 3.5) in the server_handlers.pyc endpoint of QNAP TS‑453E NAS devices leaks sensitive internal information via error messages. The vulnerability can be triggered by a network‑adjacent attacker who bypasses authentication and supplies a crafted rr2s.kwargs parameter.

Exploitability – The vulnerability is publicly disclosed; proof‑of‑concept code was demonstrated during the Pwn2Own competition. No known wild‑fire exploits, but the authentication bypass makes exploitation feasible for motivated attackers.

Affected Products – QNAP TS‑453E (single‑bay NAS).

TPRM Impact – Organizations that rely on QNAP TS‑453E for file storage, backup, or application hosting may inadvertently expose configuration details, credentials, or other sensitive data to adversaries. The disclosed information can be chained with other weaknesses to achieve arbitrary code execution under the RR2 administrator account, creating a supply‑chain foothold.

Recommended Actions –

1. Deploy QNAP’s security advisory update (QSA‑25‑46) immediately.
2. Verify the patch is applied by checking firmware version 5.x.x or later.
3. Restrict network access to the NAS (e.g., VLAN segmentation, firewall rules limiting inbound traffic to trusted subnets).
4. Disable or harden any unnecessary services that expose the server_handlers.pyc endpoint.
5. Enable comprehensive logging and monitor for unexpected error messages that contain internal data.
6. Conduct a rapid risk assessment of any third‑party processes that ingest data from the affected NAS.

Source: Zero Day Initiative Advisory ZDI‑26‑242