GHSA-v8w9-8mx6-g223
ADVISORY - githubSummary
Summary
When using parseBody({ dot: true }) in HonoRequest, specially crafted form field names such as __proto__.x could create objects containing a __proto__ property.
If the parsed result is later merged into regular JavaScript objects using unsafe merge patterns, this may lead to prototype pollution in the target object.
Details
The parseBody({ dot: true }) feature supports dot notation to construct nested objects from form field names.
In previous versions, the __proto__ path segment was not filtered. As a result, specially crafted keys such as __proto__.x could produce objects containing __proto__ properties.
While this behavior does not directly modify Object.prototype within Hono itself, it may become exploitable if the parsed result is later merged into regular JavaScript objects using unsafe merge patterns.
Impact
Applications that merge parsed form data into regular objects using unsafe patterns (for example recursive deep merge utilities) may become vulnerable to prototype pollution.
Common Weakness Enumeration (CWE)
Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution')
GitHub
2.2
CVSS SCORE
4.8medium| Package | Type | OS Name | OS Version | Affected Ranges | Fix Versions |
|---|---|---|---|---|---|
| hono | npm | - | - | <4.12.7 | 4.12.7 |
CVSS:3 Severity and metrics
The CVSS metrics represent different qualitative aspects of a vulnerability that impact the overall score, as defined by the CVSS Specification.
The vulnerable component is bound to the network stack, but the attack is limited at the protocol level to a logically adjacent topology. This can mean an attack must be launched from the same shared physical (e.g., Bluetooth or IEEE 802.11) or logical (e.g., local IP subnet) network, or from within a secure or otherwise limited administrative domain (e.g., MPLS, secure VPN to an administrative network zone). One example of an Adjacent attack would be an ARP (IPv4) or neighbor discovery (IPv6) flood leading to a denial of service on the local LAN segment (e.g., CVE-2013-6014).
A successful attack depends on conditions beyond the attacker's control, requiring investing a measurable amount of effort in research, preparation, or execution against the vulnerable component before a successful attack.
The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files of the vulnerable system to carry out an attack.
The vulnerable system can be exploited without interaction from any user.
An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
There is some loss of confidentiality. Access to some restricted information is obtained, but the attacker does not have control over what information is obtained, or the amount or kind of loss is limited. The information disclosure does not cause a direct, serious loss to the impacted component.
Modification of data is possible, but the attacker does not have control over the consequence of a modification, or the amount of modification is limited. The data modification does not have a direct, serious impact on the impacted component.
There is no impact to availability within the impacted component.