CVE-2023-26158
First published: Fri Dec 08 2023(Updated: )
All versions of the package mockjs are vulnerable to Prototype Pollution via the Util.extend function due to missing check if the attribute resolves to the object prototype. By adding or modifying attributes of an object prototype, it is possible to create attributes that exist on every object, or replace critical attributes with malicious ones. This can be problematic if the software depends on existence or non-existence of certain attributes, or uses pre-defined attributes of object prototype (such as hasOwnProperty, toString or valueOf). User controlled inputs inside the extend() method of the Mock.Handler, Mock.Random, Mock.RE.Handler or Mock.Util, will allow an attacker to exploit this vulnerability. Workaround By using a denylist of dangerous attributes, this weakness can be eliminated. Add the following line in the Util.extend function: js js if (["__proto__", "constructor", "prototype"].includes(name)) continue js // src/mock/handler.js Util.extend = function extend() { var target = arguments[0] || {}, i = 1, length = arguments.length, options, name, src, copy, clone if (length === 1) { target = this i = 0 } for (; i < length; i++) { options = arguments[i] if (!options) continue for (name in options) { if (["__proto__", "constructor", "prototype"].includes(name)) continue src = target[name] copy = options[name] if (target === copy) continue if (copy === undefined) continue if (Util.isArray(copy) || Util.isObject(copy)) { if (Util.isArray(copy)) clone = src && Util.isArray(src) ? src : [] if (Util.isObject(copy)) clone = src && Util.isObject(src) ? src : {} target[name] = Util.extend(clone, copy) } else { target[name] = copy } } } return target }
Credit: report@snyk.io
| Affected Software | Affected Version | How to fix |
|---|---|---|
| npm/mockjs | <=1.1.0 | |
| Mock.js | <=1.1.0 |
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Reference Links
- https://security.snyk.io/vuln/SNYK-JS-MOCKJS-6051365
- https://github.com/nuysoft/Mock/blob/00ce04b92eb464e664a4438430903f2de96efb47/dist/mock.js%23L721-L755
- https://nvd.nist.gov/vuln/detail/CVE-2023-26158
- https://github.com/nuysoft/Mock/blob/00ce04b92eb464e664a4438430903f2de96efb47/dist/mock.js#L721-L755
- https://github.com/advisories/GHSA-mh8j-9jvh-gjf6 (Advisory)
Frequently Asked Questions
What is the severity of CVE-2023-26158?
CVE-2023-26158 is classified as a moderate severity vulnerability due to its potential for Prototype Pollution.
How do I fix CVE-2023-26158?
To fix CVE-2023-26158, update the mockjs package to version 1.1.1 or later where the vulnerability is patched.
What impact does CVE-2023-26158 have on applications?
CVE-2023-26158 can allow an attacker to modify or add attributes to the Object prototype, potentially affecting all objects in the application, leading to unexpected behavior.
Which versions of mockjs are affected by CVE-2023-26158?
All versions of the mockjs package up to and including 1.1.0 are affected by CVE-2023-26158.
Is CVE-2023-26158 a common vulnerability?
CVE-2023-26158 illustrates a common issue known as Prototype Pollution which can occur in many JavaScript libraries, making it a notable concern for developers.
- collector/mitre-cve
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