CVE-2021-21246
CVE-2021-21246 — Pre-Auth Access token leak
OneDev is an all-in-one devops platform. In OneDev before version 4.0.3, the REST UserResource endpoint performs a security check to make sure that only administrators can list user details. However for the `/users/{id}` endpoint there are no security checks enforced so it is possible to retrieve arbitrary user details including their Access Tokens! These access tokens can be used to access the API or clone code in the build spec via the HTTP(S) protocol. It has permissions to all projects accessible by the user account. This issue may lead to `Sensitive data leak` and leak the Access Token which can be used to impersonate the administrator or any other users. This issue was addressed in 4.0.3 by removing user info from restful api.
Published Updated Sources: cvelistV5, GitHub_M
Triage
Is it exploited, how likely is exploitation, what does it touch, and how severe do the scoring sources call it.
Exploitation
Unreported
no source claims exploitation
EPSS
49%
chance of exploitation in 30 days
CVSS base
8.6
HIGH
Affected scope
The catalog records vendors and products as separate lists, not pairs, so which product belongs to which vendor is not something this page can say.
Vendors (1)
Products (1)
Every base score collected
Sources score independently and disagree; each row says who scored it and under which version.
| Score | Version | Severity | Expl. | Impact | Source |
|---|---|---|---|---|---|
| 8.6 | CVSS 3.1 | HIGH | — | — | cvelistV5 |
Weakness & attack patterns
- CWE-862
Attack patterns reported against this CVE. The ATT&CK techniques below are inferred from its weakness class.
- T1211Exploitation for Defensive Evasion
- T1542.002Pre-OS Boot: Component Firmware
- T1556Modify Authentication Process
Detection
Read off the CVSS vector and the weakness class. Starting points, not rules we have tested.
- Search application, proxy, and WAF logs for requests touching /users/.
References
2 on the record
Elsewhere on this site
Not in any source we poll
Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.
- No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
- No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
- No exploit packet captures, log samples, or incident case IDs supplied.