CVE-2021-23568 json
Prototype Pollution
published 2022-01-07 4 y ago modified 2026-09-10 1 mo ago also GHSA-gjm5-83cw-p3p2 , EUVD-2022-0606
- cvss
- 7.3
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 1.5%
- EPSS 1.5% chance of exploitation in 30 days, percentile 74%
- public exploits
- 0
- none known
Summary
The package extend2 before 1.0.1 are vulnerable to Prototype Pollution via the extend function due to unsafe recursive merge.
Patch / fix
- npm extend2 1.0.1
- n/a extend2 1.0.1
- github.com/eggjs/extend2@aa332a5 commit
- github.com/eggjs/extend2#2 pull request
Exploit prediction
1.50% chance of exploitation in the next 30 days, higher than 74% of all scored CVEs (FIRST EPSS, 2026-11-08).
Exploits and checks
- snyk.io https://snyk.io/vuln/SNYK-JS-EXTEND2-2320315 referenced PoC, tagged "exploit" by a source, unverified
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 7.3 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L/E:P |
| CNA | 3.1 | 7.3 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L |
| NVD | 3.1 | 9.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
| NVD | 2.0 | 7.5 | AV:N/AC:L/Au:N/C:P/I:P/A:P |
| GitHub | 3.1 | 7.3 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| npm | extend2 | <1.0.1 |
1.0.1 |
Affected products
- n/a extend2
Classification
- Weakness
-
- CWE-1321 Improperly Controlled Modification of Object Prototype Attributes
References
-
github.com
/eggjs/extend2/commit/aa332a59116c8398976434b57ea477c6823054f8
web, patch, third-party-advisory
-
github.com
/eggjs/extend2/pull/2
web, issue-tracking, patch, third-party-advisory
-
snyk.io
/vuln/SNYK-JS-EXTEND2-2320315
web, exploit, third-party-advisory
-
github.com
/eggjs/extend2/blob/master/index.js%23L50-L60
web, broken-link
-
nvd.nist.gov
/vuln/detail/CVE-2021-23568
advisory
-
github.com
/eggjs/extend2
package
Sources
- CVE List CVE-2021-23568
- GitHub Advisory GHSA-gjm5-83cw-p3p2
- NVD CVE-2021-23568
Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.