Prototype Pollution in immer

CVE-2021-23436 → View on GitHub ↗ View on CVE.org ↗ View on NVD ↗

Description

This affects the package immer before 9.0.6. A type confusion vulnerability can lead to a bypass of CVE-2020-28477 when the user-provided keys used in the path parameter are arrays. In particular, this bypass is possible because the condition (p === "__proto__" || p === "constructor") in applyPatches_ returns false if p is ['__proto__'] (or ['constructor']). The === operator (strict equality operator) returns false if the operands have different type.

Basic information

Type
reviewed
Severity
critical
Advisory on GitHub
Open advisory ↗
Repository advisory
—
Source code
Browse source ↗
Published (advisory)
2021-09-02 17:17:37 UTC
Updated
2024-04-30 20:26:07 UTC
GitHub reviewed
2021-09-02 16:57:31 UTC
NVD published
2021-09-01

EPSS Score

Score Percentile
0.10% 27.10%

CVSS Scores

Base score Version Severity Vector
9.8 3.1 —
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.

Identifiers

Type Value
GHSA GHSA-33f9-j839-rf8h ↗
CVE CVE-2021-23436 ↗

CWEs

CWE id Name
CWE-843 Access of Resource Using Incompatible Type ('Type Confusion')
CWE-1321 Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution')

Credits

  • levpachmanov (analyst)

Affected packages (1)

Vulnerable version ranges and first patched releases as published by GitHub.

Ecosystem Package Vulnerable range First patched Vulnerable functions
npm immer >= 7.0.0, < 9.0.6 9.0.6 —

References

cvelogic Threat Intelligence