CVE-2021-28099In Netflix OSS Hollow, since the Files.exists(parent) is run before creating the directories, an attacker can pre-create these directories…
- 4.4MediumCVSS base score
- 0.25%Exploitation in 30 daysEPSS · top 83% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
Description
In Netflix OSS Hollow, since the Files.exists(parent) is run before creating the directories, an attacker can pre-create these directories with wide permissions. Additionally, since an insecure source of randomness is used, the file names to be created can be deterministically calculated.
Timeline
ID reserved
By netflix
- 14 days later
· 14 days later
Published
- 3 years later
· 3 years later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| NVDNVD · Modified | 3.1 | Medium4.4 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N |
- EPSS (exploitation in 30 days)
- 0.25% · top 83% of all CVEs (14 Nov 2026)
The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 4.4.
Affected products
Netflix OSS Hollow
- affected All versions
Affected packages
From reviewed advisories of the GitHub Advisory Database.
- Mavencom.netflix.hollow:hollowGHSA-9295-mhf3-v33m (opens in a new tab)
References
References1
- https://github.com/Netflix/security-bulletins/blob/master/advisories/nflx-2021-001.md (opens in a new tab)x_refsource_MISCx_transferred
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2021-0635 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisory GHSA-9295-mhf3-v33m (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2021-28099)Record last updated .