CyberSecBulletin
CVE-2024-27307NVD status: Analyzed

jsonata: Improperly Controlled Modification of Object Prototype Attributes

Published Updated By the CyberSecBulletin desk

CVE-2024-27307 is a critical-severity improperly controlled modification of object prototype attributes vulnerability in jsonata from Jsonata-js, with a CVSS 3.1 base score of 9.8 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected jsonata versions: >= 1.4.0, < 1.8.7; >= 2.0.0, < 2.0.4. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 1.42% chance of exploitation within 30 days, higher than 73% of scored CVEs.

Patch this week

Critical severity: a successful attack would have severe impact.

What to do

  1. Update jsonata to 1.8.7 or 2.0.4, whichever matches your release line, or a later version.
  2. Read the advisory on github.com for workarounds and exact fixed builds.
  3. Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.

Affected products and versions

VendorProductAffected versionsFixed in
Jsonata-jsjsonata>= 1.4.0, < 1.8.7; >= 2.0.0, < 2.0.4Not stated
Jsonatajsjsonata1.4.0 up to, but not including, 1.8.7; 2.0.0 up to, but not including, 2.0.41.8.7, 2.0.4

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
NetworkCan be exploited remotely over a network, including the internet.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
NoneNo account or login is needed.
User interaction
NoneNo action by a victim is required.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
HighAll data handled by the component can be read.
Integrity
HighData or code can be modified at will.
Availability
HighThe component can be taken down completely.

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H. Scored by CNA (github.com).

Official description

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.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Improperly Controlled Modification of Object Prototype Attributes

The product receives input from an upstream component that specifies attributes that are to be initialized or updated in an object, but it does not properly control modifications of attributes of the object prototype.

How developers prevent this class of flaw

  • By freezing the object prototype first (for example, Object.freeze(Object.prototype)), modification of the prototype becomes impossible.
  • By blocking modifications of attributes that resolve to object prototype, such as proto or prototype, this weakness can be mitigated.
  • When handling untrusted objects, validating using a schema can be used.

More Improperly Controlled Modification of Object Prototype Attributes vulnerabilities (CWE-1321)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: total).
  3. Record last changed materially (score, affected products, status or references).

References

Other vulnerabilities in jsonata

All jsonata vulnerabilities

Recent Improperly Controlled Modification of Object Prototype Attributes vulnerabilities

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