CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
AI Score
Confidence
High
EPSS
Percentile
16.3%
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.
Vendor | Product | Version | CPE |
---|---|---|---|
boa | boa_engine | * | cpe:2.3:a:boa:boa_engine:*:*:*:*:*:*:*:* |