Attack ChainAIDerived
Hypothetical attack flow derived from CVE metadata – not a confirmed exploit chain
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AccessGain adjacent network access to router management interface
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DeliveryAuthenticate with valid router credentials
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ExploitCraft JSON-RPC request invoking restricted operation
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ExecutionSubmit request directly to firmware API bypassing GUI authorization layer
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ImpactRead sensitive system files or execute arbitrary OS commands
Vulnerability Assessment
| Weakness |
CWE
OWASP Top 10:2025
A01:2025 - Broken Access Control
ASVS 5.0
V8 - Authorization Authorization logic validation
MITRE ATT&CK
1 technique across 1 tactic: Privilege Escalation The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up. |
| Exploitation Conditions | Exploitation requires two prerequisites: the attacker must possess valid authentication credentials for the KAON router (the vendor CVSS 4.0 vector specifies PR:H, suggesting high-privilege credentials, though 'authenticated user' in the description is ambiguous - direct vendor confirmation is needed to determine if any authenticated session suffices), and the attacker must have adjacent network access (AV:A) to the router's management interface, meaning physical or logical LAN adjacency. The vulnerable interface is the JSON-RPC endpoint exposed by the router firmware. Devices where management interfaces are isolated to a dedicated out-of-band network, or where management access is restricted by ACL to specific administrative hosts, are not reachable by this attack path. Internet-facing exploitation is not applicable due to the adjacent-network constraint. |
| Impact | The vendor-supplied CVSS 4.0 vector (AV:A/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H) scores 8.5, reflecting adjacent-network attack surface with high privileges required but full confidentiality, integrity, and availability impact on the vulnerable system. The AV:A constraint substantially limits the exploitable population - an attacker must have network-adjacent access to the router management interface, ruling out opportunistic internet-scale scanning. A notable tension exists in the data: the vendor CVSS 4.0 vector specifies PR:H (high privilege), but the description states only 'authenticated user,' without distinguishing between administrative and lower-privilege accounts; security teams should verify with KAON whether this affects any authenticated session or only privileged ones, as that distinction materially changes exposure. No CISA KEV listing and no public POC code exist, indicating no confirmed mass exploitation. EPSS data was not provided in available intelligence. Despite low exploitation evidence, router compromise via arbitrary command execution is particularly severe in ISP and enterprise deployments because it enables persistent backdoors and interception of all downstream traffic, making patch deployment urgent regardless of EPSS signal. |
| Exploit ScenarioDerived | An attacker who has obtained valid router credentials - through default password use, credential reuse, or prior phishing - and is positioned on the same network segment as the router's management interface crafts a JSON-RPC request invoking a privileged operation (such as reading /etc/shadow or executing a shell command) that the GUI would normally block. The router's firmware processes the request without enforcing the same authorization checks applied by the GUI, returning sensitive file contents or executing the command with elevated privileges. No public exploit code exists at time of analysis, but the technique requires only knowledge of the JSON-RPC API schema and valid credentials. |
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Alert meAnalysisAIv1 – Aug 24, 2026
Incorrect authorization in KAON PG5298A and PG5298B router firmware allows authenticated network-adjacent users to send crafted JSON-RPC requests that bypass GUI-enforced access controls, enabling arbitrary system file reads and command execution on the device. All firmware versions prior to 3.0.82 (PG5298A) and 4.0.82 (PG5298B) are affected, as confirmed by CERT-PL. No public exploit has been identified at time of analysis; vendor-released patches are available.
RemediationAI
Upgrade PG5298A firmware to version 3.0.82 or later and PG5298B firmware to version 4.0.82 or later; these versions are confirmed as the fixes per the CVE description and CERT-PL advisory at https://cert.pl/en/posts/2026/08/CVE-2025-63080/. As a compensating control while patching, restrict network access to the router's management interface (including the JSON-RPC endpoint) at the network layer, permitting connections only from dedicated management hosts or out-of-band management VLANs - this directly addresses the AV:A attack vector by reducing adjacency. Disabling or firewalling the web management interface entirely from untrusted LAN segments is a high-efficacy mitigation with the trade-off of requiring out-of-band or console access for configuration changes. Review access logs for unexpected JSON-RPC requests that do not correspond to normal GUI-driven activity as an indicator of exploitation attempts.
Affected VersionsENISA
Affected Packages
Source: OSV (Open Source Vulnerabilities)
Affects your stack
Affects 2 packages in euvd
Checking this CVE against your own stacks and servers is part of the Basic plan and up.
Technical ContextAI · show details
KAON PG5298A and PG5298B are carrier-grade or ISP-deployed routers whose firmware exposes a JSON-RPC interface for programmatic device management. CWE-863 (Incorrect Authorization) identifies the root cause: the firmware fails to enforce adequate authorization checks on JSON-RPC operations, allowing authenticated users to invoke privileged functions that the web GUI correctly restricts. This is a classic API-vs-GUI authorization mismatch - the GUI layer implements role-based restrictions that the underlying JSON-RPC handler does not replicate, creating an authorization bypass path through direct API access. Affected CPEs are cpe:2.3:a:kaon:pg5298a:*:*:*:*:*:*:*:* and cpe:2.3:a:kaon:pg5298b:*:*:*:*:*:*:*:*, covering all pre-patch firmware versions on both hardware variants.
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Severity by source
CVSS:4.0/AV:A/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
Adjacent network and authenticated access required; PR:L used because description states 'authenticated user' without confirming high-privilege requirement, pending vendor clarification; full C/I/A from file read and command execution.
Primary rating from Vendor (CERT-PL).
CVSS VectorVendor: CERT-PL
Lifecycle Timeline
2DescriptionCVE.org
Firmware in KAON PG5298A and PG5298B routers allow an authenticated user to send crafted JSON-RPC requests and perform operations not possible via GUI, e.g. system file read or command execution. This vulnerability has been fixed in firmware version: 3.0.82 for PG5298A and 4.0.82 for PG5298B.
Executive ViewAI
KAON router firmware versions PG5298A and PG5298B contain an authorization bypass vulnerability (CVSS 8.5) that enables authenticated network users to read arbitrary system files and execute commands by sending crafted JSON-RPC requests, potentially compromising all affected network infrastructure. Organizations operating these routers face immediate risk of unauthorized system access, configuration tampering, and lateral network movement by internal or adjacent-network attackers.
Vendor-released patch: update KAON PG5298A firmware to version 3.0.82 or later; update KAON PG5298B firmware to version 4.0.82 or later. Interim mitigations pending patch deployment: restrict network access to JSON-RPC API endpoints to trusted administrative networks; disable GUI remote management where possible and enforce MFA on all administrative accounts.
Threat Intelligence Overview
How this decision was reached
The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.
What every action level means
SSVC AssessmentENISA
Priority Score
Attack Technique
Authentication bypass attacks exploit flaws in the verification mechanisms that control access to systems and applications.
EUVD-2025-210761
GHSA-qr3p-6238-2p49
NVD
CVE.org
EPSS
Vulnrichment
VulDB
Exploit-DB