Unraid Authentication Bypass
CVE-2020-5849 is a high-severity incorrect comparison vulnerability in Unraid, with a CVSS 3.1 base score of 7.5 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected Unraid versions: 6.8.0. The record does not name a fixed version, so check the vendor advisory. CISA added it to the Known Exploited Vulnerabilities catalogue on November 3, 2021, which means attacks have been observed in the wild.
Attackers are already exploiting this vulnerability, according to CISA.
What to do
- Check which version of Unraid you run against the affected versions below, and install the vendor's latest release.
- CISA's required action: Apply updates per vendor instructions.
- Read the advisory on forums.unraid.net for workarounds and exact fixed builds.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
Version data comes from NVD's product matching. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- NoneNothing can be modified.
- Availability
- NoneAvailability is not affected.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 7.5 | High | NVD |
| CVSS 3.1 | 7.5 | High | CISA (ADP) |
| CVSS 2.0 | 5.0 | Medium | NVD |
Official description
Unraid 6.8.0 allows authentication bypass.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Incorrect Comparison
The product compares two entities in a security-relevant context, but the comparison is incorrect.
Timeline
- CVE record published.
- Added to CISA's Known Exploited Vulnerabilities catalogue.
- Deadline for US federal agencies to remediate, set by CISA.
- CISA published its SSVC assessment (exploitation: active, automatable: yes, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Advisories
- forums.unraid.net/forum/7-announcements/Release Notes
Third-party and government advisories
- sysdream.com/news/lab/Third Party Advisory
- cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2020-5849US Government Resource
Technical write-ups (may include proof of concept)
- packetstormsecurity.com/files/157275/Unraid-6.8.0-Authentication-Bypass-Arbitrary-Code-Execution.htmlExploit, Third Party Advisory, VDB Entry
Other vulnerabilities in Unraid
- 8.8 High severity
- 8.8 High severity
- 7.3 High severity
- 8.8 High severity
- 9.6 Critical severity
- 9.8 Critical severity
Unraid Remote Code Execution Exploited
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