Docker
CVE-2021-21284
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 6.8 (MEDIUM). Attack characteristics: adjacent network attack vector, low complexity, low privileges required, no user interaction not required. |
| Exploit ScenarioDerived | An attacker could exploit this vulnerability to access files and directories outside the intended path. |
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Alert meAnalysisAI
In Docker before versions 9.03.15, 20.10.3 there is a vulnerability involving the --userns-remap option in which access to remapped root allows privilege escalation to real root. Rated medium severity (CVSS 6.8), this vulnerability is low attack complexity. This Path Traversal vulnerability could allow attackers to access files and directories outside the intended path.
RemediationAI
A vendor patch is available. Apply the latest security update as soon as possible. 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 go
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. In Docker before versions 9.03.15, 20.10.3 there is a vulnerability involving the --userns-remap option in which access to remapped root allows privilege escalation to real root. When using "--userns-remap", if the root user in the remapped namespace has access to the host filesystem they can modify files under "/var/lib/docker/<remapping>" that cause writing files with extended privileges. Versions 20.10.3 and 19.03.15 contain patches that prevent privilege escalation from remapped user. Affected products include: Docker, Debian Debian Linux, Netapp E-Series Santricity Os Controller.
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Severity by source
AV:A/AC:L/PR:L/UI:N/S:C/C:N/I:H/A:N
Primary rating from NVD · only source for this CVE.
CVSS VectorNVD
DescriptionNVD
In Docker before versions 9.03.15, 20.10.3 there is a vulnerability involving the --userns-remap option in which access to remapped root allows privilege escalation to real root. When using "--userns-remap", if the root user in the remapped namespace has access to the host filesystem they can modify files under "/var/lib/docker/<remapping>" that cause writing files with extended privileges. Versions 20.10.3 and 19.03.15 contain patches that prevent privilege escalation from remapped user.
Threat Intelligence Overview
NVD
CVE.org
EPSS
GitHub
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
Privilege escalation occurs when an attacker leverages flaws in access control mechanisms to gain permissions beyond what they were originally granted.
Path traversal exploits occur when applications use user-controlled input to construct file system paths without proper validation.
Affected Products (CPE)NVD
An issue was discovered in Appsmith before 1.52. Rated critical severity (CVSS 9.8), this vulnerability is remotely expl
runc through version 1.0-rc6 (used in Docker before 18.09.2) contains a container escape vulnerability that allows attac
Netmaker makes networks with WireGuard. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no a
Unauthenticated remote code execution in Marimo ≤0.20.4 allows attackers to execute arbitrary system commands via the `/
The News & Blog Designer Pack - WordPress Blog Plugin - (Blog Post Grid, Blog Post Slider, Blog Post Carousel, Blog Post
Path traversal in JFrog Artifactory (CWE-22) enables an authenticated low-privilege user to write data outside the inten
Docker 1.3.2 allows remote attackers to execute arbitrary code with root privileges via a crafted (1) image or (2) build
Remote code execution in Gogs through 0.14.2 allows authenticated users (and unauthenticated attackers on default-config
Unauthenticated remote command injection in SGWBOX N3 firmware 2.0.25 lets attackers execute arbitrary operating-system
Remote code execution in Flowise before 3.1.2 allows any authenticated user (or API caller with chatflow view/update per
Remote code execution in NocoBase Workflow Script Node (npm @nocobase/plugin-workflow-javascript) allows authenticated l
Docker Desktop Community Edition before 2.1.0.1 allows local users to gain privileges by placing a Trojan horse docker-c
Exploit-DB