CVE-2021-32708
A public proof of concept exists; no exploitation attested.
- Published2021-06-24
- Fixed in2.1.1 · 1.1.4
- WeaknessCWE-367
Am I affected?
Debian, Ubuntu or Red Hat sometimes backport a fix without changing the upstream version number: such a version reads « to verify », never « affected ».With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.
Description
Flysystem is an open source file storage library for PHP. The whitespace normalisation using in 1.x and 2.x removes any unicode whitespace. Under certain specific conditions this could potentially allow a malicious user to execute code remotely. The conditions are: A user is allowed to supply the path or filename of an uploaded file, the supplied path or filename is not checked against unicode chars, the supplied pathname checked against an extension deny-list, not an allow-list, the supplied path or filename contains a unicode whitespace char in the extension, the uploaded file is stored in a directory that allows PHP code to be executed. Given these conditions are met a user can upload and execute arbitrary code on the system under attack. The unicode whitespace removal has been replaced with a rejection (exception). For 1.x users, upgrade to 1.1.4. For 2.x users, upgrade to 2.1.1.
Timeline
dates in UTC- 2021-06-2417:15CVE publishedNVD
- 2026-10-2319:23First public proof of conceptPoC-in-GitHub
Observed activity
isMalicious corpus · updated 2026-10-23 21:37 UTCBlock these indicators
- Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2021-32708?format=txt
- CSV export: https://api.ismalicious.com/edl/cve/CVE-2021-32708?format=csv
- TAXII collection of exploited CVEs
- The EDL and CSV take an API key on the Pro plan.
Versions per branch
NVD · OSV| Branch | Affected | Fixed in | Source |
|---|---|---|---|
| 2.x | ≥ 2.0.0, < 2.1.1 | 2.1.1 | NVD · OSV |
| 1.x | ≥ 1.0.0, < 1.1.4 | 1.1.4 | NVD |
| 1.1 | < 1.1.4 | 1.1.4 | OSV |
| Branch | Affected | Fixed in | Source |
|---|---|---|---|
| 33.x | = 33 | no fix published | NVD |
| 34.x | = 34 | no fix published | NVD |
as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.
Fix
- Update Thephpleague flysystem to 2.1.1 · 1.1.4
Advisories and patches
- github.comPatch
- github.comPatch
- github.comPatch
Detection
read 2026-10-23 19:23 UTC- Nuclei template
- none so far ProjectDiscovery
- Exploit-DB
- no entry Exploit-DB
Sources
- CNACVSS 3.19.8read 2026-10-23
- NVDCVSS 3.18.1read 2026-10-23
- NVDCVSS 2.09.3read 2026-10-23
- CNAweakness (CWE)CWE-367read 2026-10-23
- NVDweakness (CWE)CWE-367read 2026-10-23
- FIRST EPSSEPSS score3.5 %2026-10-23
- PoC-in-GitHubproof of concept1read 2026-10-23
- OSVaffected packages—
Technical details
- CVSS v3 Vector
- CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
- Published
- 2021-06-24
- Last Modified
- 2026-06-17
- NVD status
- Modified
Frequently asked questions
What is CVE-2021-32708?
Is CVE-2021-32708 actively exploited?
What is the CVSS score for CVE-2021-32708?
Running league/flysystem? Hear about its next vulnerability
Surveillance reads the versions in your stack — a domain, a lockfile or a list — checks each CVE against the ranges its sources publish, and alerts you when one you run is exploited or enters CISA KEV. A version it cannot read stays « version not verified ».
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Related vulnerabilities
Same product first, then the same vendor advisory and the same publication week.