CVE-2018-14645
Description
A flaw was discovered in the HPACK decoder of haproxy, before 1.8.14, that is used for HTTP/2. An out-of-bounds read access in hpack_valid_idx() resulted in a remote crash and denial of service.
Statement
HTTP/2 support was added to haproxy in version 1.8, therefore OpenShift Container Platform (OCP) 3.7 and earlier are unaffected by this flaw. OCP 3.11 added a configuration option to ose-haproxy-router that made enabling HTTP/2 support easy, [2]. Prior to that, in versions OCP 3.9 and 3.10, an administrator had to customize the haproxy router configuration to add HTTP/2 support, [3]. OCP 3.9, and 3.10 are rated as moderate because HTTP/2 support was not a standard configuration option, and therefore unlikely to be enabled.
Versions of haproxy included in Red Hat Enterprise Linux 6 and 7, excluding rh-haproxy18-haproxy in Red Hat Software Collections, are unaffected as they package versions of haproxy before 1.7.
[1] http://www.haproxy.org/news.html
Mitigation
HTTP/2 support is disabled by default on OpenShift Container Platform 3.11. To mitigate this vulnerability keep it disabled. You can verify if HTTP/2 support is enabled by following the instructions in the upstream pull request, [1].
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 | 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:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
NVD: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
cve.org: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Acknowledgements
Red Hat would like to thank Tim Düsterhus and Willy Tarreau for reporting this issue.
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