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Use-after-free in some host call implementations

Moderate
elliottt published GHSA-mp3g-vpm9-9vqv Jun 26, 2024

Package

npm @fastly/js-compute (npm)

Affected versions

>= 3.0.0, < 3.16.0

Patched versions

3.16.0

Description

Impact

The implementation of the following functions were determined to include a use-after-free bug:

  • FetchEvent.client.tlsCipherOpensslName
  • FetchEvent.client.tlsProtocol
  • FetchEvent.client.tlsClientCertificate
  • FetchEvent.client.tlsJA3MD5
  • FetchEvent.client.tlsClientHello
  • CacheEntry.prototype.userMetadata of the fastly:cache subsystem
  • Device.lookup of the fastly:device subsystem

This bug could allow for an unintended data leak if the result of the preceding functions were sent anywhere else, and often results in a Compute service crash causing an HTTP 500 error to be returned. As all requests to Compute are isolated from one another, the only data at risk is data present for a single request.

Patches

This bug has been fixed in version 3.16.0 of the @fastly/js-compute package.

Workarounds

There are no workarounds for this bug, any use of the affected functions introduces the possibility of a data leak or crash in guest code.

Severity

Moderate

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v3 base metrics

Attack vector
Network
Attack complexity
High
Privileges required
High
User interaction
Required
Scope
Unchanged
Confidentiality
Low
Integrity
Low
Availability
High

CVSS v3 base metrics

Attack vector: More severe the more the remote (logically and physically) an attacker can be in order to exploit the vulnerability.
Attack complexity: More severe for the least complex attacks.
Privileges required: More severe if no privileges are required.
User interaction: More severe when no user interaction is required.
Scope: More severe when a scope change occurs, e.g. one vulnerable component impacts resources in components beyond its security scope.
Confidentiality: More severe when loss of data confidentiality is highest, measuring the level of data access available to an unauthorized user.
Integrity: More severe when loss of data integrity is the highest, measuring the consequence of data modification possible by an unauthorized user.
Availability: More severe when the loss of impacted component availability is highest.
CVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:U/C:L/I:L/A:H

CVE ID

CVE-2024-38375

Weaknesses

No CWEs

Credits