Actively exploited in the wild
QNAP NAS Improper Authorization Vulnerability
QNAP - Network Attached Storage (NAS) · Listed in the CISA KEV since 2022-03-31. This indicates confirmed attacks in production environments.
Required action: Apply updates per vendor instructions.
CVE-2021-28799
CriticalCVSS 10.0KEVSummary
An improper authorization vulnerability has been reported in QNAP NAS running HBS 3 (Hybrid Backup Sync). If exploited, the vulnerability allows remote attackers to log in to a device without proper authorization.
Risk Assessment
An unauthenticated remote attacker could gain access to the QNAP NAS device interface, potentially leading to data theft or further privilege escalation within the organization's network.
Recommendation
Update HBS 3 to at least v16.0.0415 (QTS 4.5.2), v3.0.210412 (QTS 4.3.6), v3.0.210411 (QTS 4.3.4/4.3.3), v16.0.0419 (QuTS hero h4.5.1), or v16.0.0419 (QuTScloud c4.5.1~c4.5.4). If updating is not possible, restrict network access to the HBS 3 service.
Related vulnerabilities
- CVE-2026-121606Critical
A vulnerability was found in Qihoo 360 devices (models D621-2, D603-2, D600-2, D619, D606-6 and D706 up to 6.4.9) in the verify_sign function of fs2/bin/iscm responsible for firmware signature verification. Manipulating the sign argument leads to improper verification of cryptographic signatures. The attack can be launched remotely and the exploit has been publicly disclosed.
- CVE-2026-121600Critical
A vulnerability was found in TOTOLINK A950RG version 4.1.2cu.5268_B20221104 in the setMacFilterRules function of /cgi-bin/cstecgi.cgi handling MAC filtering. Manipulating the addEffect argument causes a stack-based buffer overflow. The attack can be initiated remotely and the exploit is publicly available.
- CVE-2026-121599Critical
A vulnerability was detected in TOTOLINK A950RG version 4.1.2cu.5268_B20221104 in the setWiFiMultipleConfig/delWiFiMultipleConfig functions of /cgi-bin/cstecgi.cgi handling Multi-SSID configuration. Manipulating the wepkey2/wepkey3 arguments results in a stack-based buffer overflow. The attack can be launched remotely and the exploit is now public.
- CVE-2026-121598Critical
A security vulnerability was detected in TOTOLINK A950RG version 4.1.2cu.5268_B20221104 in the strcpy function of /cgi-bin/cstecgi.cgi handling basic wireless configuration. Manipulating the wepkey argument leads to a stack-based buffer overflow. The attack can be initiated remotely and the exploit has been publicly disclosed.
- CVE-2026-92190Critical
Quest Foglight for Databases contains a deserialization of untrusted data vulnerability in the baseRmiServiceExporter component. An unauthenticated remote attacker can execute arbitrary code in the context of SYSTEM.
- CVE-2026-92189Critical
In Quest Foglight for Databases, the writeTopologySectionToFile method does not validate a user-supplied path before using it in file operations. An unauthenticated remote attacker can execute arbitrary code in the context of SYSTEM.
- CVE-2026-92188Critical
The ForgeMBeanServerSupport module in Quest Foglight for Databases lacks authentication before allowing access to functionality. An unauthenticated remote attacker can execute arbitrary code in the context of SYSTEM.
- CVE-2026-121597Critical
In TOTOLINK A950RG version 4.1.2cu.5268_B20221104, the setAppEasyWizardConfig function in /cgi-bin/cstecgi.cgi mishandles the functionType argument, leading to a stack-based buffer overflow. The attack can be performed remotely and a public exploit is available.
- CVE-2026-114549Critical
The NoMachine nxwebrunner web service (listening on TCP port 4443 by default) contains a heap-based buffer overflow due to lack of validation of user-supplied data length. An unauthenticated remote attacker can execute arbitrary code in the context of the service account.
- CVE-2022-29966Critical
Emerson Ovation has several protocols that have no authentication, which could allow an attacker to change controller configuration or cause a denial-of-service condition.
Original NVD description (English source)
An improper authorization vulnerability has been reported to affect QNAP NAS running HBS 3 (Hybrid Backup Sync. ) If exploited, the vulnerability allows remote attackers to log in to a device. This issue affects: QNAP Systems Inc. HBS 3 versions prior to v16.0.0415 on QTS 4.5.2; versions prior to v3.0.210412 on QTS 4.3.6; versions prior to v3.0.210411 on QTS 4.3.4; versions prior to v3.0.210411 on QTS 4.3.3; versions prior to v16.0.0419 on QuTS hero h4.5.1; versions prior to v16.0.0419 on QuTScloud c4.5.1~c4.5.4. This issue does not affect: QNAP Systems Inc. HBS 2 . QNAP Systems Inc. HBS 1.3 .
Vulnerability data from NVD (NIST) · CISA KEV · EPSS

