Umbraco Cms
CVE-2020-5811
MEDIUM
Vulnerability Assessment
| Weakness |
CWE
OWASP Top 10:2025
A01:2025 - Broken Access Control
ASVS 5.0
V5 - File Handling Path canonicalization, traversal prevention
MITRE ATT&CK
2 techniques across 2 tactics: Discovery, Collection The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up. |
| Impact | CVSS score of 6.5 (MEDIUM). Attack characteristics: network attack vector, low complexity, low privileges required, no user interaction not required. Public proof-of-concept exploit code is available. |
| Exploit ScenarioDerived | A remote attacker could access files and directories outside the intended path by sending crafted requests to the affected application. |
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Alert meAnalysisAI
An authenticated path traversal vulnerability exists during package installation in Umbraco CMS <= 8.9.1 or current, which could result in arbitrary files being written outside of the site home and. Rated medium severity (CVSS 6.5), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
RemediationAI
No vendor patch is available at time of analysis. Monitor vendor advisories for updates. Validate and canonicalize file paths. Use chroot or sandboxing. Reject input containing path separators or '../' sequences.
Affected Packages
Source: OSV (Open Source Vulnerabilities)
Affects your stack
Affects 1 package in nuget
Checking this CVE against your own stacks and servers is part of the Basic plan and up.
Technical ContextAI · show details
This vulnerability is classified as Path Traversal (CWE-22), which allows attackers to access files and directories outside the intended path. An authenticated path traversal vulnerability exists during package installation in Umbraco CMS <= 8.9.1 or current, which could result in arbitrary files being written outside of the site home and expected paths when installing an Umbraco package. Affected products include: Umbraco Umbraco Cms.
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- Exploit and PoC references, threat intelligence from 22 sources
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Severity by source
AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N
Primary rating from NVD · only source for this CVE.
CVSS VectorNVD
DescriptionNVD
An authenticated path traversal vulnerability exists during package installation in Umbraco CMS <= 8.9.1 or current, which could result in arbitrary files being written outside of the site home and expected paths when installing an Umbraco package.
Threat Intelligence Overview
How this decision was reached
The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.
What every action level means
SSVC AssessmentENISA
Priority Score
Attack Technique
Path traversal exploits occur when applications use user-controlled input to construct file system paths without proper validation.
Affected Products (CPE)NVD
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NVD
CVE.org
EPSS
Exploit-DB
GitHub PoC