Cyber Resilience

CVE-2021-43807

HighPublic PoC

Published: 14 December 2021

Published
14 December 2021
Modified
21 November 2024
KEV Added
Patch
CVSS Score v3.1 7.5 CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H
EPSS Score 0.0039 60.4th percentile
Risk Priority 15 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2021-43807 is a high-severity Authentication Bypass by Spoofing (CWE-290) vulnerability in Apereo Opencast. Its CVSS base score is 7.5 (High).

Operationally, ranked in the top 39.6% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

EU & UK References

Vulnerability details

Opencast is an Open Source Lecture Capture & Video Management for Education. Opencast versions prior to 9.10 allow HTTP method spoofing, allowing to change the assumed HTTP method via URL parameter. This allows attackers to turn HTTP GET requests into…

more

PUT requests or an HTTP form to send DELETE requests. This bypasses restrictions otherwise put on these types of requests and aids in cross-site request forgery (CSRF) attacks, which would otherwise not be possible. The vulnerability allows attackers to craft links or forms which may change the server state. This issue is fixed in Opencast 9.10 and 10.0. You can mitigate the problem by setting the `SameSite=Strict` attribute for your cookies. If this is a viable option for you depends on your integrations. We strongly recommend updating in any case.

CWE(s)

Related Threats

No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.

Affected Assets

apereo
opencast
≤ 9.10

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

addresses: CWE-290

Reveals spoofed logon attempts through unexpected previous logon timestamps upon legitimate login.

addresses: CWE-290

Training specifically addresses recognizing spoofed communications and phishing that enable authentication bypass.

addresses: CWE-290

Requiring verifiable identity evidence at appropriate assurance levels makes it substantially harder for attackers to successfully spoof or impersonate users to obtain accounts.

addresses: CWE-290

Unique device authentication makes successful spoofing of device identity substantially more difficult to achieve.

addresses: CWE-290

Unique identification of non-organizational users reduces the feasibility of authentication bypass by spoofing.

addresses: CWE-290

Unique identification and authentication of services before communications makes spoofing of service identities substantially harder.

addresses: CWE-290

Isolated trusted path ensures the user interacts only with genuine system components, preventing spoofing of authentication interfaces or prompts.

addresses: CWE-290

Directly counters DNS response spoofing by requiring cryptographic origin authentication artifacts from the authoritative source.

References