Boa is an embeddable and experimental Javascript engine written in Rust. Starting in version 0.16 and prior to version 0.19.0, a wrong assumption made when handling ECMAScript's `AsyncGenerator` operations can cause an uncaught exception on certain scripts. Boa's implementation of `AsyncGenerator` makes the assumption that the state of an `AsyncGenerator` object cannot change while resolving a promise created by methods of `AsyncGenerator` such as `%AsyncGeneratorPrototype%.next`, `%AsyncGeneratorPrototype%.return`, or `%AsyncGeneratorPrototype%.throw`. However, a carefully constructed code could trigger a state transition from a getter method for the promise's `then` property, which causes the engine to fail an assertion of this assumption, causing an uncaught exception. This could be used to create a Denial Of Service attack in applications that run arbitrary ECMAScript code provided by an external user. Version 0.19.0 is patched to correctly handle this case. Users unable to upgrade to the patched version would want to use `std::panic::catch_unwind` to ensure any exceptions caused by the engine don't impact the availability of the main application.
History

Tue, 20 Aug 2024 16:30:00 +0000

Type Values Removed Values Added
First Time appeared Boa
Boa boa
CPEs cpe:2.3:a:boa:boa:*:*:*:*:*:*:*:*
Vendors & Products Boa
Boa boa
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Thu, 15 Aug 2024 21:00:00 +0000

Type Values Removed Values Added
Description Boa is an embeddable and experimental Javascript engine written in Rust. Starting in version 0.16 and prior to version 0.19.0, a wrong assumption made when handling ECMAScript's `AsyncGenerator` operations can cause an uncaught exception on certain scripts. Boa's implementation of `AsyncGenerator` makes the assumption that the state of an `AsyncGenerator` object cannot change while resolving a promise created by methods of `AsyncGenerator` such as `%AsyncGeneratorPrototype%.next`, `%AsyncGeneratorPrototype%.return`, or `%AsyncGeneratorPrototype%.throw`. However, a carefully constructed code could trigger a state transition from a getter method for the promise's `then` property, which causes the engine to fail an assertion of this assumption, causing an uncaught exception. This could be used to create a Denial Of Service attack in applications that run arbitrary ECMAScript code provided by an external user. Version 0.19.0 is patched to correctly handle this case. Users unable to upgrade to the patched version would want to use `std::panic::catch_unwind` to ensure any exceptions caused by the engine don't impact the availability of the main application.
Title Boa has an uncaught exception when transitioning the state of `AsyncGenerator` objects
Weaknesses CWE-248
References
Metrics cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'}


cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published: 2024-08-15T20:38:23.530Z

Updated: 2024-08-20T15:45:24.595Z

Reserved: 2024-08-09T14:23:55.513Z

Link: CVE-2024-43367

cve-icon Vulnrichment

Updated: 2024-08-20T15:45:18.006Z

cve-icon NVD

Status : Awaiting Analysis

Published: 2024-08-15T21:15:17.777

Modified: 2024-08-19T13:00:23.117

Link: CVE-2024-43367

cve-icon Redhat

No data.