Apache HTTP Server vulnerabilities
71 known vulnerabilities in Apache HTTP Server from Apache. 71 are rated high or critical, and 5 have been exploited in real attacks. Each entry lists the affected versions and the release that fixes it, where the vendor has published one.
Latest first
- 7.5 High severity
Apache HTTP Server: Server-Side Request Forgery
Server-Side Request Forgery (SSRF) in Apache HTTP Server on Windows allows to potentially leak NTLM hashes to a malicious server via mod_rewrite or apache expressions that pass unvalidated request input. This issue affects Apache HTTP Server: from 2.4.0 throug
- 7.5 High severity
Apache HTTP Server: Server-Side Request Forgery
SSRF in Apache HTTP Server with mod_proxy loaded allows an attacker to send outbound proxy requests to a URL controlled by the attacker. Requires an unlikely configuration where mod_headers is configured to modify the Content-Type request or response header wi
- 7.5 High severity
HTTP response splitting in the core of Apache HTTP Server allows an attacker who can…
HTTP response splitting in the core of Apache HTTP Server allows an attacker who can manipulate the Content-Type response headers of applications hosted or proxied by the server can split the HTTP response. This vulnerability was described as CVE-2023-38709 bu
- 7.5 High severity
Apache HTTP Server: Server-Side Request Forgery
SSRF in Apache HTTP Server on Windows with mod_rewrite in server/vhost context, allows to potentially leak NTML hashes to a malicious server via SSRF and malicious requests. Users are recommended to upgrade to version 2.4.62 which fixes this issue.
- 7.5 High severity
Potential SSRF in mod_rewrite in Apache HTTP Server 2.4.59 and earlier allows an attacker to…
Potential SSRF in mod_rewrite in Apache HTTP Server 2.4.59 and earlier allows an attacker to cause unsafe RewriteRules to unexpectedly setup URL's to be handled by mod_proxy. Users are recommended to upgrade to version 2.4.60, which fixes this issue.
- 7.5 High severity
Apache HTTP Server: NULL Pointer Dereference
null pointer dereference in mod_proxy in Apache HTTP Server 2.4.59 and earlier allows an attacker to crash the server via a malicious request. Users are recommended to upgrade to version 2.4.60, which fixes this issue.
- 9.8 Critical severity
Apache HTTP Server: Inclusion of Functionality from Untrusted Control Sphere
Vulnerability in core of Apache HTTP Server 2.4.59 and earlier are vulnerably to information disclosure, SSRF or local script execution via backend applications whose response headers are malicious or exploitable. Users are recommended to upgrade to version 2.
- 9.1 Critical severity
Apache HTTP Server Improper Escaping of Output Exploited
Improper escaping of output in mod_rewrite in Apache HTTP Server 2.4.59 and earlier allows an attacker to map URLs to filesystem locations that are permitted to be served by the server but are not intentionally/directly reachable by any URL, resulting in code
- 9.8 Critical severity
Apache HTTP Server: Improper Encoding or Escaping of Output
Substitution encoding issue in mod_rewrite in Apache HTTP Server 2.4.59 and earlier allows attacker to execute scripts in directories permitted by the configuration but not directly reachable by any URL or source disclosure of scripts meant to only to be execu
- 8.1 High severity
Apache HTTP Server: Improper Encoding or Escaping of Output
Encoding problem in mod_proxy in Apache HTTP Server 2.4.59 and earlier allows request URLs with incorrect encoding to be sent to backend services, potentially bypassing authentication via crafted requests. Users are recommended to upgrade to version 2.4.60, wh
- 7.5 High severity
Apache HTTP Server: Server-Side Request Forgery
SSRF in Apache HTTP Server on Windows allows to potentially leak NTLM hashes to a malicious server via SSRF and malicious requests or content Users are recommended to upgrade to version 2.4.60 which fixes this issue. Note: Existing configurations that access U
- 7.5 High severity
Apache HTTP Server: Allocation of Resources Without Limits or Throttling
HTTP/2 incoming headers exceeding the limit are temporarily buffered in nghttp2 in order to generate an informative HTTP 413 response. If a client does not stop sending headers, this leads to memory exhaustion.
- 7.3 High severity
Apache HTTP Server: Improper Validation of Specified Quantity in Input
Faulty input validation in the core of Apache allows malicious or exploitable backend/content generators to split HTTP responses. This issue affects Apache HTTP Server: through 2.4.58.
- 7.5 High severity
Apache HTTP Server: Uncontrolled Resource Consumption
An attacker, opening a HTTP/2 connection with an initial window size of 0, was able to block handling of that connection indefinitely in Apache HTTP Server. This could be used to exhaust worker resources in the server, similar to the well known "slow loris" at
- 7.5 High severity
Apache HTTP Server: Inconsistent Interpretation of HTTP Requests
HTTP Response Smuggling vulnerability in Apache HTTP Server via mod_proxy_uwsgi. This issue affects Apache HTTP Server: from 2.4.30 through 2.4.55. Special characters in the origin response header can truncate/split the response forwarded to the client.
- 9.8 Critical severity
Apache HTTP Server: Inconsistent Interpretation of HTTP Requests
Some mod_proxy configurations on Apache HTTP Server versions 2.4.0 through 2.4.55 allow a HTTP Request Smuggling attack. Configurations are affected when mod_proxy is enabled along with some form of RewriteRule or ProxyPassMatch in which a non-specific pattern
- 9.0 Critical severity
Apache HTTP Server: Inconsistent Interpretation of HTTP Requests
Inconsistent Interpretation of HTTP Requests ('HTTP Request Smuggling') vulnerability in mod_proxy_ajp of Apache HTTP Server allows an attacker to smuggle requests to the AJP server it forwards requests to. This issue affects Apache HTTP Server Apache HTTP Ser
- 9.8 Critical severity
Apache HTTP Server: Insufficient Verification of Data Authenticity
Apache HTTP Server 2.4.53 and earlier may not send the X-Forwarded-* headers to the origin server based on client side Connection header hop-by-hop mechanism. This may be used to bypass IP based authentication on the origin server/application.
- 7.5 High severity
Apache HTTP Server: Exposure of Sensitive Information to an Unauthorized Actor
Apache HTTP Server 2.4.53 and earlier may return lengths to applications calling r:wsread() that point past the end of the storage allocated for the buffer.
- 7.5 High severity
Apache HTTP Server: Allocation of Resources Without Limits or Throttling
If Apache HTTP Server 2.4.53 is configured to do transformations with mod_sed in contexts where the input to mod_sed may be very large, mod_sed may make excessively large memory allocations and trigger an abort.
- 7.5 High severity
Apache HTTP Server: Allocation of Resources Without Limits or Throttling
In Apache HTTP Server 2.4.53 and earlier, a malicious request to a lua script that calls r:parsebody(0) may cause a denial of service due to no default limit on possible input size.
- 9.1 Critical severity
Apache HTTP Server: Integer Overflow or Wraparound
Apache HTTP Server 2.4.53 and earlier may crash or disclose information due to a read beyond bounds in ap_strcmp_match() when provided with an extremely large input buffer. While no code distributed with the server can be coerced into such a call, third-party
- 7.5 High severity
Apache HTTP Server: Inconsistent Interpretation of HTTP Requests
Inconsistent Interpretation of HTTP Requests ('HTTP Request Smuggling') vulnerability in mod_proxy_ajp of Apache HTTP Server allows an attacker to smuggle requests to the AJP server it forwards requests to. This issue affects Apache HTTP Server Apache HTTP Ser
- 9.8 Critical severity
Apache HTTP Server: Out-of-bounds Write
Out-of-bounds Write vulnerability in mod_sed of Apache HTTP Server allows an attacker to overwrite heap memory with possibly attacker provided data. This issue affects Apache HTTP Server 2.4 version 2.4.52 and prior versions.
- 9.1 Critical severity
Apache HTTP Server: Integer Overflow or Wraparound
If LimitXMLRequestBody is set to allow request bodies larger than 350MB (defaults to 1M) on 32 bit systems an integer overflow happens which later causes out of bounds writes. This issue affects Apache HTTP Server 2.4.52 and earlier.
- 9.8 Critical severity
Apache HTTP Server: Inconsistent Interpretation of HTTP Requests
Apache HTTP Server 2.4.52 and earlier fails to close inbound connection when errors are encountered discarding the request body, exposing the server to HTTP Request Smuggling
- 7.5 High severity
Apache HTTP Server: Improper Initialization
A carefully crafted request body can cause a read to a random memory area which could cause the process to crash. This issue affects Apache HTTP Server 2.4.52 and earlier.
- 9.8 Critical severity
Apache HTTP Server Path Traversal Exploited
It was found that the fix for CVE-2021-41773 in Apache HTTP Server 2.4.50 was insufficient. An attacker could use a path traversal attack to map URLs to files outside the directories configured by Alias-like directives. If files outside of these directories ar
- 9.8 Critical severity
Apache HTTP Server Path Traversal Exploited
A flaw was found in a change made to path normalization in Apache HTTP Server 2.4.49. An attacker could use a path traversal attack to map URLs to files outside the directories configured by Alias-like directives. If files outside of these directories are not
- 9.0 Critical severity
Apache HTTP Server-Side Request Forgery (SSRF) Exploited
A crafted request uri-path can cause mod_proxy to forward the request to an origin server choosen by the remote user. This issue affects Apache HTTP Server 2.4.48 and earlier.
- 7.8 High severity
Apache HTTP Server Privilege Escalation Exploited
In Apache HTTP Server 2.4 releases 2.4.17 to 2.4.38, with MPM event, worker or prefork, code executing in less-privileged child processes or threads (including scripts executed by an in-process scripting interpreter) could execute arbitrary code with the privi