CVE-2024-27307: JSONata expression can pollute the "Object" prototype
Impact
In JSONata versions >= 1.4.0, < 1.8.7 and >= 2.0.0, < 2.0.4, a malicious expression can use the transform operator to override properties on the Object constructor and prototype. This may lead to denial of service, remote code execution or other unexpected behavior in applications that evaluate user-provided JSONata expressions.
Patch
This issue has been fixed in JSONata versions >= 1.8.7 and >= 2.0.4. Applications that evaluate user-provided expressions should update ASAP to prevent exploitation. The following patch can be applied if updating is not possible.
patch --- a/src/jsonata.js +++ b/src/jsonata.js @@ -1293,6 +1293,13 @@ var jsonata = (function() { } for(var ii = 0; ii < matches.length; ii++) { var match = matches[ii]; + if (match && (match.isPrototypeOf(result) || match instanceof Object.constructor)) { + throw { + code: "D1010", + stack: (new Error()).stack, + position: expr.position + }; + } // evaluate the update value for each match var update = await evaluate(expr.update, match, environment); // update must be an object @@ -1539,7 +1546,7 @@ var jsonata = (function() { if (typeof err.token == 'undefined' && typeof proc.token !== 'undefined') { err.token = proc.token; } - err.position = proc.position; + err.position = proc.position || err.position; } throw err; } @@ -1972,6 +1979,7 @@ var jsonata = (function() { "T1007": "Attempted to partially apply a non-function. Did you mean ${{{token}}}?", "T1008": "Attempted to partially apply a non-function", "D1009": "Multiple key definitions evaluate to same key: {{value}}", + "D1010": "Attempted to access the Javascript object prototype", // Javascript specific "T1010": "The matcher function argument passed to function {{token}} does not return the correct object structure", "T2001": "The left side of the {{token}} operator must evaluate to a number", "T2002": "The right side of the {{token}} operator must evaluate to a number",
References
https://github.com/jsonata-js/jsonata/releases/tag/v2.0.4
Credit
Thank you to Albert Pedersen of Cloudflare for disclosing this issue.
Other sources
JSONata is a JSON query and transformation language. Starting in version 1.4.0 and prior to version 1.8.7 and 2.0.4, a malicious expression can use the transform operator to override properties on the Object constructor and prototype. This may lead to denial of service, remote code execution or other unexpected behavior in applications that evaluate user-provided JSONata expressions. This issue has been fixed in JSONata versions 1.8.7 and 2.0.4. Applications that evaluate user-provided expressions should update ASAP to prevent exploitation. As a workaround, one may apply the patch manually.
— NVD
Affected Software
Remediation
Event History
Frequently Asked Questions
What is the severity of CVE-2024-27307?
CVE-2024-27307 has a moderate severity rating due to the potential for denial of service when exploiting the vulnerability.
How do I fix CVE-2024-27307?
To fix CVE-2024-27307, update your JSONata package to version 2.0.4 or later, or to version 1.8.7 or later if you are using a version from the 1.x series.
Which versions of JSONata are affected by CVE-2024-27307?
CVE-2024-27307 affects JSONata versions greater than or equal to 1.4.0 and less than 1.8.7, as well as versions greater than or equal to 2.0.0 and less than 2.0.4.
What kind of attack can be executed using CVE-2024-27307?
CVE-2024-27307 allows an attacker to execute a malicious expression that overrides properties on the Object constructor and prototype, potentially leading to denial of service.
Is CVE-2024-27307 specific to any particular platform?
CVE-2024-27307 is specific to the JSONata library and can be exploited in any application that uses vulnerable versions of the library.