CVE-2021-21322
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Description
A flaw was found in fastify-http-proxy. Escaping the prefix of the proxied backend service is possible by an attacker using a specially crafted URL. The highest threat from this vulnerability is to data confidentiality and integrity.
Statement
The impact of this flaw largely depends on the environment where the affected library is being used. This flaw could be used to redirect an adversary to an exposed, unprotected endpoint. Depending on the functionality of the affected endpoint that could result in a loss of confidentiality, integrity and availability. The severity of this flaw in for Red Had Advanced Cluster Management for Kubernetes is rated as important as there are no exposed, un-authenticated endpoints that could be accessed by exploiting this flaw.
Additional information
- Bugzilla 1942182: fastify-http-proxy: crafted URL allows prefix scape of the proxied backend service
- CWE-20: Improper Input Validation
- FAQ: Frequently asked questions about CVE-2021-21322
Common Vulnerability Scoring System (CVSS) Score Details
Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
| Red Hat | NVD | |
|---|---|---|
CVSS v3 Base Score | 10 | 9.8 |
Attack Vector | Network | Network |
Attack Complexity | Low | Low |
Privileges Required | None | None |
User Interaction | None | None |
Scope | Changed | Unchanged |
Confidentiality Impact | High | High |
Integrity Impact | High | High |
Availability Impact | None | High |
CVSS v3 Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:N
NVD: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Red Hat CVSS v3 Score Explanation
The CVSSv3 score applied by Red Hat originates from the original rating assigned in the GitHub Security advisory.
Understanding the Weakness (CWE)
Availability
Technical Impact: DoS: Crash, Exit, or Restart; DoS: Resource Consumption (CPU); DoS: Resource Consumption (Memory)
An attacker could provide unexpected values and cause a program crash or excessive consumption of resources, such as memory and CPU.
Confidentiality
Technical Impact: Read Memory; Read Files or Directories
An attacker could read confidential data if they are able to control resource references.
Integrity,Confidentiality,Availability
Technical Impact: Modify Memory; Execute Unauthorized Code or Commands
An attacker could use malicious input to modify data or possibly alter control flow in unexpected ways, including arbitrary command execution.
Frequently Asked Questions
Why is Red Hat's CVSS v3 score or Impact different from other vendors?
My product is listed as "Under investigation" or "Affected", when will Red Hat release a fix for this vulnerability?
What can I do if my product is listed as "Will not fix"?
What can I do if my product is listed as "Fix deferred"?
What is a mitigation?
I have a Red Hat product but it is not in the above list, is it affected?
Why is my security scanner reporting my product as vulnerable to this vulnerability even though my product version is fixed or not affected?
My product is listed as "Out of Support Scope". What does this mean?
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