A vulnerability was found in httpd's handling of the LimitRequestFields directive in mod_http2, affecting servers with HTTP/2 enabled. An attacker could send crafted requests with headers larger than the server's available memory, causing httpd to crash.
Find out more about CVE-2016-8740 from the MITRE CVE dictionary dictionary and NIST NVD.
Red Hat Product Security has rated this issue as having Low security
impact. This issue is not currently planned to be addressed in future
updates. For additional information, refer to the Issue Severity
Classification: https://access.redhat.com/security/updates/classification/.
| Base Score | 4.3 |
|---|---|
| Base Metrics | AV:N/AC:M/Au:N/C:N/I:N/A:P |
| Access Vector | Network |
| Access Complexity | Medium |
| Authentication | None |
| Confidentiality Impact | None |
| Integrity Impact | None |
| Availability Impact | Partial |
| CVSS3 Base Score | 5.9 |
|---|---|
| CVSS3 Base Metrics | CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H |
| Attack Vector | Network |
| Attack Complexity | High |
| Privileges Required | None |
| User Interaction | None |
| Scope | Unchanged |
| Confidentiality | None |
| Integrity Impact | None |
| Availability Impact | High |
Find out more about Red Hat support for the Common Vulnerability Scoring System (CVSS).
| Platform | Errata | Release Date |
|---|---|---|
| Red Hat JBoss Core Services on RHEL 7 Server | RHSA-2017:1413 | 2017-06-07 |
| Red Hat Software Collections for Red Hat Enterprise Linux 7 (httpd24-httpd) | RHSA-2017:1161 | 2017-04-26 |
| Red Hat JBoss Core Services 1 | RHSA-2017:1415 | 2017-06-07 |
| Red Hat JBoss Core Services on RHEL 6 Server | RHSA-2017:1414 | 2017-06-07 |
| Red Hat Software Collections for Red Hat Enterprise Linux 6 (httpd24-httpd) | RHSA-2017:1161 | 2017-04-26 |
| Platform | Package | State |
|---|---|---|
| Red Hat JBoss Web Server 3 | httpd24 | Not affected |
| Red Hat JBoss Web Server 3 | httpd | Not affected |
| Red Hat JBoss EWS 2 | httpd | Not affected |
| Red Hat JBoss EWS 2 | httpd22 | Not affected |
| Red Hat JBoss EWS 1 | httpd | Not affected |
| Red Hat JBoss EAP 6 | httpd22 | Not affected |
| Red Hat JBoss EAP 6 | httpd | Not affected |
| Red Hat JBoss EAP 5 | httpd | Not affected |
| Red Hat Enterprise Linux 7 | httpd | Not affected |
| Red Hat Enterprise Linux 6 | httpd | Not affected |
| Red Hat Enterprise Linux 5 | httpd | Not affected |
| Red Hat Directory Server 8 | httpd | Not affected |
As a temporary workaround - HTTP/2 can be disabled by changing
the configuration by removing h4 and h4c from the Protocols
line(s) in the configuration file.
The resulting line should read:
Protocols http/1.1
Vulmon