- Reported
-
- Issued
-
- Package
-
boa_engine
(crates.io)
- Type
-
Vulnerability
- Categories
-
- Aliases
-
- References
-
- Related
-
- CVSS Score
- 8.6
HIGH
- CVSS Details
-
- Attack Vector
- Network
- Attack Complexity
- Low
- Privileges Required
- None
- User Interaction
- None
- Scope
- Unchanged
- Confidentiality Impact
- Low
- Integrity Impact
- Low
- Availability Impact
- High
- CVSS Vector
- CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:H
- Patched
-
- Unaffected
-
Description
A wrong assumption made when handling ECMAScript's AsyncGenerator operations
can cause an uncaught exception on certain scripts.
Details
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.
Patches
Version 0.19.0 is patched to correctly handle this case.
Workarounds
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.
Advisory available under CC-BY-4.0
license.
Source: https://github.com/boa-dev/boa/security/advisories/GHSA-f67q-wr6w-23jq