CVE-2023-45288
Description
A vulnerability was discovered with the implementation of the HTTP/2 protocol in the Go programming language. There were insufficient limitations on the amount of CONTINUATION frames sent within a single stream. An attacker could potentially exploit this to cause a Denial of Service (DoS) attack.
Statement
Red Hat rates the security impact of this vulnerability as Important due to the worst case scenario resulting in a denial of service. It is simple to exploit, could significantly impact availability, and there is not a suitable mitigation for all use cases. Once an attack has ended, the system should return to normal operations on its own.
This vulnerability only impacts servers which have HTTP/2 enabled. It stems from an imperfect definition of the protocol. As the Go programming language is widely utilized across nearly every major Red Hat offering, a full listing of impacted packages will not be provided. Therefore, the “Affected Packages and Issued Red Hat Security Errata” section contains a simplified list of what offerings need to remediate this vulnerability. Every impacted offering has at least one representative component listed, but potentially not all of them. Rest assured that Red Hat is committed to remediating this vulnerability across our entire portfolio.
Many components are rated as Low impact due to configurations which reduce the attack surface or significantly increase the difficulty of exploitation. A summary of these scenarios are:
- The container includes a package that provides a vulnerable webserver, but it is not used or running during operation
- HTTP/2 is disabled by default and is not supported
- Only a client implementation is provided, which is not vulnerable
- A vulnerable module (either golang.org/net/http or golang.org/x/net/http2) is included, but disabled
- Access to a vulnerable server is restricted within the container (loopback only connections)
- Golang is available in the container but is not used
Within the Red Hat OpenShift Container Platform, the majority of vulnerable components are not externally accessible. This means an attacker must already have access to a container within your environment to exploit this vulnerability. However, the ose-hyperkube (openshift-enterprise-hyperkube) container is externally accessible, so there are less barriers to exploitation. Fixes for this specific container are already available.
Within Red Hat Ansible Automation Platform, the impacted component is Receptor. The impact has been reduced to Low as the vulnerable code is present, but not utilized. There are three potential exposures within this component:
- Receptor utilizes QUIC a UDP based protocol which does not run over HTTP/2
- Receptor utilizes the x/net/ipv4 and ipv6 packages, both of which are not affected
Mitigation
In some environments where http/2 support is not required, it may be possible to disable this feature to reduce risk.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert: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).
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 7.5 | N/A | 7.5 |
| Attack Vector | Network | N/A | Network |
| Attack Complexity | Low | N/A | Low |
| Privileges Required | None | N/A | None |
| User Interaction | None | N/A | None |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | None | N/A | None |
| Integrity Impact | None | N/A | None |
| Availability Impact | High | N/A | High |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
cve.org: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Understanding the Weakness (CWE)
Availability
Technical Impact: DoS: Crash, Exit, or Restart; DoS: Resource Consumption (CPU); DoS: Resource Consumption (Memory); DoS: Resource Consumption (Other)
If an attacker can trigger the allocation of the limited resources, but the number or size of the resources is not controlled, then the most common result is denial of service. This would prevent valid users from accessing the product, and it could potentially have an impact on the surrounding environment, i.e., the product may slow down, crash due to unhandled errors, or lock out legitimate users. For example, a memory exhaustion attack against an application could slow down the application as well as its host operating system.
Access Control,Other
Technical Impact: Bypass Protection Mechanism; Other
In some cases it may be possible to force the product to "fail open" in the event of resource exhaustion. The state of the product -- and possibly the security functionality - may then be compromised.
Acknowledgements
Red Hat would like to thank Bartek Nowotarski (nowotarski.info) for reporting this issue.
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