Quantum Secular Labs / Blog / Advisories
CVE-2026-87827: A remote unauthenticated attacker with network access to the affected service can execute arbitrary system…
CVE-2026-87827 is rated critical with a CVSS v4.0 base score of 10.0. Per its scoring, it can be exploited over the network, without authentication, without any user interaction. The scored impact on confidentiality, integrity and availability is the highest available.
Vulnerability description
Certain KGUARD DVR devices running vulnerable firmware expose a system command execution service on all network interfaces without requiring authentication. A remote unauthenticated attacker with network access to the affected service can execute arbitrary system commands on the device, potentially resulting in complete compromise of the DVR. The vulnerability is known to have been exploited in the wild by the Mirai_ptea (Rimasuta) and Mirai_aurora botnets for malware propagation and subsequent DDoS activity. The vulnerability was reported to affect firmware dating from 2016, while firmware released after 2017 appears to mitigate the issue by restricting the affected service to the localhost interface (127.0.0.1) instead of exposing it on all interfaces (0.0.0.0). The affected-device list reported by Netlab includes many D1004NR, D1008NR, D1016NR, D1104, D1104NR, D1108NR, D1116NR, D1132NR, D2116NR, D97xx, D98xx, and D99xx variants and several associated hardware revisions The exploit is included in some version of rapperbot and exploited in 2026. This assignment has been made to document the active exploitation and lack of documentation from the vendor.
Severity breakdown
CVSS v4.0 10.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
- Attack vector: Network. Exploitable remotely over the network.
- Attack complexity: Low. No special conditions; the attack can be repeated reliably.
- Attack requirements: None. No deployment or execution conditions are needed.
- Privileges required: None. No account or prior access is needed.
- User interaction: None. No action from any user is needed.
- Confidentiality impact (vulnerable system): High. Total loss of confidentiality.
- Integrity impact (vulnerable system): High. Total loss of integrity.
- Availability impact (vulnerable system): High. Total loss of availability.
- Confidentiality impact (subsequent systems): High. Total loss of confidentiality on other systems.
- Integrity impact (subsequent systems): High. Total loss of integrity on other systems.
- Availability impact (subsequent systems): High. Total loss of availability of other systems.
Underlying weakness
CWE-1188: Initialization of a Resource with an Insecure Default
The product initializes or sets a resource with a default that is intended to be changed by the product's installer, administrator, or maintainer, but the default is not secure.