Use-after-free in Apache HTTP Server

Published: 2017-09-20 | Updated: 2017-10-03
Risk Low
Patch available YES
Number of vulnerabilities 1
CVE-ID CVE-2017-9798
Exploitation vector Network
Public exploit Public exploit code for vulnerability #1 is available.
Vulnerable software
Apache HTTP Server
Server applications / Web servers

Vendor Apache Foundation

Security Bulletin

This security bulletin contains one low risk vulnerability.

1) Use-after-free


Risk: Low


CVE-ID: CVE-2017-9798

CWE-ID: CWE-416 - Use After Free

Exploit availability: Yes


The vulnerability allows a remote attacker to obtain potentially sensitive information.

The vulnerability exists due to use-after-free error when processing HTTP OPTIONS requests in server/core.c, when limits are configured in .htaccess or httpd.conf configuration files. A remote unauthenticated attacker can read portions of memory through HTTP OPTIONS requests and gain access to potentially sensitive data.

The vulnerability is dubbed Optionsbleed.


Update to version 2.4.28.

Vulnerable software versions

Apache HTTP Server: 2.2.0 - 2.4.27

CPE2.3 External links

Q & A

Can this vulnerability be exploited remotely?

How the attacker can exploit this vulnerability?

Is there known malware, which exploits this vulnerability?