What’s Vulnerable › Vulnerabilities

CVE-2020-7765: Prototype Pollution

• Severity: medium (CVSS 5.3 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.6% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2020-11-16 · updated 2026-06-17

Description

This affects the package @firebase/util before 0.3.4. This vulnerability relates to the deepExtend function within the DeepCopy.ts file. Depending on if user input is provided, an attacker can overwrite and pollute the object prototype of a program.

Affected products

• Google Firebase/Util: before 0.3.4 — fixed in 0.3.4

How to fix

Upgrade to a fixed version: Google Firebase/Util 0.3.4. Check the vendor advisory for mitigations.

References

• https://github.com/firebase/firebase-js-sdk/commit/9cf727fcc3d049551b16ae0698ac33dc2fe45ada
• https://github.com/firebase/firebase-js-sdk/pull/4001
• https://snyk.io/vuln/SNYK-JS-FIREBASEUTIL-1038324
• https://github.com/firebase/firebase-js-sdk/commit/9cf727fcc3d049551b16ae0698ac33dc2fe45ada
• https://github.com/firebase/firebase-js-sdk/pull/4001
• https://snyk.io/vuln/SNYK-JS-FIREBASEUTIL-1038324

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