Arch Linux Security Advisory ASA-201804-4 ========================================= Severity: Medium Date : 2018-04-04 CVE-ID : CVE-2017-15710 CVE-2017-15715 CVE-2018-1283 CVE-2018-1301 CVE-2018-1302 CVE-2018-1303 CVE-2018-1312 Package : apache Type : multiple issues Remote : Yes Link : https://security.archlinux.org/AVG-664 Summary ======= The package apache before version 2.4.33-1 is vulnerable to multiple issues including session hijacking, access restriction bypass, content spoofing and denial of service. Resolution ========== Upgrade to 2.4.33-1. # pacman -Syu "apache>=2.4.33-1" The problems have been fixed upstream in version 2.4.33. Workaround ========== None. Description =========== - CVE-2017-15710 (denial of service) 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, mod_authnz_ldap, 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. - CVE-2017-15715 (access restriction bypass) In Apache httpd 2.4.0 before 2.4.30, the expression specified in <FilesMatch> could match '$' to a newline character in a malicious filename, rather than matching only the end of the filename. This could be exploited in environments where uploads of some files are externally blocked, but only by matching the trailing portion of the filename. - CVE-2018-1283 (session hijacking) In Apache httpd 2.2.0 before 2.4.30, when mod_session is configured to forward its session data to CGI applications (SessionEnv on, not the default), a remote user may influence their content by using a "Session" header. This comes from the "HTTP_SESSION" variable name used by mod_session to forward its data to CGIs, since the prefix "HTTP_" is also used by the Apache HTTP Server to pass HTTP header fields, per CGI specifications. - CVE-2018-1301 (denial of service) A specially crafted request could have crashed the Apache HTTP Server prior to version 2.4.30, due to an out of bound access after a size limit is reached by reading the HTTP header. This vulnerability is considered very hard if not impossible to trigger in non-debug mode (both log and build level), so it is classified as low risk for common server usage. - CVE-2018-1302 (denial of service) When an HTTP/2 stream was destroyed after being handled, the Apache HTTP Server prior to version 2.4.30 could have written a NULL pointer potentially to an already freed memory. The memory pools maintained by the server make this vulnerability hard to trigger in usual configurations, the reporter and the team could not reproduce it outside debug builds, so it is classified as low risk. - CVE-2018-1303 (denial of service) A specially crafted HTTP request header could have crashed the Apache HTTP Server prior to version 2.4.30 due to an out of bound read while preparing data to be cached in shared memory. It could be used as a Denial of Service attack against users of mod_cache_socache. - CVE-2018-1312 (content spoofing) In Apache httpd 2.2.0 before 2.4.30, when generating an HTTP Digest authentication challenge, the nonce sent to prevent reply attacks was not correctly generated using a pseudo-random seed. In a cluster of servers using a common Digest authentication configuration, HTTP requests could be replayed across servers by an attacker without detection. Impact ====== A remote attacker is able to crash a server, hijack a user session, upload arbitrary files or spoof requests by providing a crafted request. References ========== https://httpd.apache.org/security/vulnerabilities_24.html https://security.archlinux.org/CVE-2017-15710 https://security.archlinux.org/CVE-2017-15715 https://security.archlinux.org/CVE-2018-1283 https://security.archlinux.org/CVE-2018-1301 https://security.archlinux.org/CVE-2018-1302 https://security.archlinux.org/CVE-2018-1303 https://security.archlinux.org/CVE-2018-1312