GHSA-whpx-q3rq-w8jc – ses

Package

Manager: npm
Name: ses
Vulnerable Version: >=0 <0.16.0

Severity

Level: Low

CVSS v3.1: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N/E:U/RL:O/RC:C

CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N

EPSS: N/A pctlN/A

Details

Hardening of TypedArrays with non-canonical numeric property names in SES ### Impact _What kind of vulnerability is it? Who is impacted?_ In Hardened JavaScript, programs can `harden` objects to safely share objects with co-tenant programs without risk of these other programs tampering with their API surface. Hardening does not guarantee that objects are pure or immutable, so a hardened `Map`, for example is superficially tamper-proof, but any party holding a reference to the object can both read and write its contents. Based on this precedent, and because `TypedArray` instances cannot be frozen with `Object.isFrozen`, `harden` does not `freeze` `TypedArrays` and instead makes them non-extensible and makes all non-indexed properties non-writable and non-configurable. This is consistent with the treatment of `Map` because the indexed properties represent mutable content and non-indexed properties represent the API. Due to a defect in `harden`, properties that have names that parse as numbers but are not the same as the canonical representation of those numbers, as in `"+0"` and `""` which are both equivalent to their canonical number `"0"`, remain writable after hardening. Any program treating one of these properties as part of its API and relying on `harden` to prevent modifications would be vulnerable to an API pollution attack, affecting only instances shared by mutually suspicious parties. Unlike a `Map`, a hardened `TypedArray` can only have numbers for content. Any program that is sharing hardened `TypedArrays` between co-tentant programs and relying on harden to only allow these programs to communicate exclusively by changing numbers within the bounds of the TypedArray, may inadvertently have arranged for a mechanism for a pair of third-parties to communicate arbitrary objects on these other properties. ### Patches _Has the problem been patched? What versions should users upgrade to?_ SES version 0.16.0 patches this issue, causing `harden` to recognize properties with non-canonical numeric representations and ensuring that these properties are non-configurable. ### Workarounds _Is there a way for users to fix or remediate the vulnerability without upgrading?_ Users should avoid sharing `TypedArrays` between co-tenant programs and instead create wrapper objects that produce a read-only view of the underlying data. We allow `harden` to succeed for `TypedArrays` because the treatment is in fact consistent with the behavior of collections like `Map`, but all collections shared between co-tentant programs should probably be attenuated to either read- or write-only facets and probably close over only part of the content of the collection. However, the motivation for allowing `TypedArrays` to be hardened in practice is to allow certain legacy modules to function under Hardened JavaScript with LavaMoat, since they export `TypedArrays`, even though they would ideally export read-only facets of these. ### References _Are there any links users can visit to find out more?_ Not at this time. ### For more information If you have any questions or comments about this advisory: * Email us at [security@agoric.com](mailto:security@agoric.com)

Metadata

Created: 2022-10-20T18:38:35Z
Modified: 2022-10-20T18:38:35Z
Source: https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2022/10/GHSA-whpx-q3rq-w8jc/GHSA-whpx-q3rq-w8jc.json
CWE IDs: []
Alternative ID: N/A
Finding: F184
Auto approve: 1