apache. Multiple issues existed in Apache. These were addressed by updating Apache to version 2.4.25.
In Apache httpd 2.0.23 to 2.0.65, 2.2.0 to 2.2.34, and 2.4.0 to 2.4.29, modauthnzldap, if configured with AuthLDAPCharsetConfig, uses the Accept-Language header value to lookup the right charset encoding when verifying the user's credentials. If the header value is not present in the charset conversion table, a fallback mechanism is used to truncate it to a two characters value to allow a quick retry (for example, 'en-US' is truncated to 'en'). A header value of less than two characters forces an out of bound write of one NUL byte to a memory location that is not part of the string. In the worst case, quite unlikely, the process would crash which could be used as a Denial of Service attack. In the more likely case, this memory is already reserved for future use and the issue has no effect at all.
A use-after free vulnerability was found in apache httpd. There's an apache configuration directive <Limit> that can be used to restrict access to certain HTTP methods. If one sets this inside an .htaccess file with an HTTP method that's not registered in the server the bug happens (e.g. set <Limit INVALID></Limit> in .htaccess). The reason is that at that point the variables used to build up the "Allow" header have already been freed, as it's not expecting any more changes to it.
Note that the bug only appears with OPTIONS requests to a specific path, not with "" OPTIONS requests.
An attacker on a shared hosting could could deliberately create an .htaccess file triggering the bug and subsequently try to exfiltrate data pieces from the global apache process that may contain secrets like password hashes.
Upstream patch:
https://svn.apache.org/viewvc?view=revision&revision=1807754
Apache HTTP Server, in all releases prior to 2.2.32 and 2.4.25, was liberal in the whitespace accepted from requests and sent in response lines and headers. Accepting these different behaviors represented a security concern when httpd participates in any chain of proxies or interacts with back-end application servers, either through modproxy or using conventional CGI mechanisms, and may result in request smuggling, response splitting and cache pollution.
apache. Multiple issues existed in Apache. These were addressed by updating Apache to version 2.4.25.
apache. Multiple issues existed in Apache. These were addressed by updating Apache to version 2.4.25.
modsessiondbd.c in the modsessiondbd module in the Apache HTTP Server before 2.4.5 proceeds with save operations for a session without considering the dirty flag and the requirement for a new session ID, which has unspecified impact and remote attack vectors.