CVE-2024-45506
Description
A flaw was found in HAProxy. An issue in the HTTP/2 multiplexer combined with the zero-copy forwarding system allows remote attackers to trigger under very rare conditions an endless loop and cause a denial of service.
Statement
The severity of this vulnerability has been raised to Important due to preliminary evidence from the upstream HAProxy project that it has been exploited in one case. Without this detail, the technical risk from this type of denial of service would have been rated Moderate.
This issue can only be triggered when zero-copy forwarding of data is enabled. See the mitigation section to see how this mechanism can be disabled.
The HAProxy package as shipped in Red Hat Enterprise Linux 7, 8, 9, in Red Hat Ceph Storage 5 and in Red Hat OpenShift Container Platform 3.11 and 4 is not affected by this vulnerability because these products do not ship a vulnerable version of HAProxy.
Mitigation
Disable the zero-copy forwarding system to mitigate this issue. Add the following configuration directive in the global section:
global
...
tune.h2.zero-copy-fwd-send off
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).
The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 7.5 | 7.5 | 7.5 |
| Attack Vector | Network | Network | Network |
| Attack Complexity | Low | Low | Low |
| Privileges Required | None | None | None |
| User Interaction | None | None | None |
| Scope | Unchanged | Unchanged | Unchanged |
| Confidentiality | None | None | None |
| Integrity Impact | None | None | None |
| Availability Impact | High | High | High |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
NVD: 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: Resource Consumption (CPU); DoS: Resource Consumption (Memory); DoS: Amplification
An infinite loop will cause unexpected consumption of resources, such as CPU cycles or memory. The software's operation may slow down, or cause a long time to respond.
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