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Apache HTTP Server vulnerabilities

352 published CVES affecting Apache HTTP Server, from public sources (CVE.org, NVD, CISA KEV, FIRST EPSS, OSV).

Total
352
Critical
31
High
131
Medium
175
Low
14
Unscored
1
CISA KEV
5

Latest Apache HTTP Server CVEs

Newest publication first · page 6 of 15

  1. HighCVSS 7.5 EPSS 14.0%

    HTTP/2 (2.4.20 through 2.4.39) very early pushes, for example configured with "H2PushResource", could lead to an overwrite of memory in the pushing request's pool, leading to crashes. The memory copied is that of the configured push link header values, not data supplied by the cl...

  2. MediumCVSS 4.2 EPSS 8.3%

    A vulnerability was found in Apache HTTP Server 2.4.34 to 2.4.38. When HTTP/2 was enabled for a http: host or H2Upgrade was enabled for h2 on a https: host, an Upgrade request from http/1.1 to http/2 that was not the first request on a connection could lead to a misconfiguration...

  3. MediumCVSS 5.3 EPSS 19.3%

    A vulnerability was found in Apache HTTP Server 2.4.17 to 2.4.38. Using fuzzed network input, the http/2 request handling could be made to access freed memory in string comparison when determining the method of a request and thus process the request incorrectly.

  4. MediumCVSS 5.3 EPSS 17.9%

    A vulnerability was found in Apache HTTP Server 2.4.0 to 2.4.38. When the path component of a request URL contains multiple consecutive slashes ('/'), directives such as LocationMatch and RewriteRule must account for duplicates in regular expressions while other aspects of the se...

  5. HighCVSS 7.8 EPSS 65.0% CISA KEV added 2021-11-03 Exploited in the wild

    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 privileges of the parent...

  6. HighCVSS 7.5 EPSS 16.4%

    In Apache HTTP Server 2.4 release 2.4.38 and prior, a race condition in mod_auth_digest when running in a threaded server could allow a user with valid credentials to authenticate using another username, bypassing configured access control restrictions.

  7. HighCVSS 7.5 EPSS 59.9%

    A bug exists in the way mod_ssl handled client renegotiations. A remote attacker could send a carefully crafted request that would cause mod_ssl to enter a loop leading to a denial of service. This bug can be only triggered with Apache HTTP Server version 2.4.37 when using OpenSS...

  8. HighCVSS 7.5 EPSS 20.0%

    In Apache HTTP Server 2.4 release 2.4.37 and prior, mod_session checks the session expiry time before decoding the session. This causes session expiry time to be ignored for mod_session_cookie sessions since the expiry time is loaded when the session is decoded.

  9. MediumCVSS 5.3 EPSS 19.4%

    In Apache HTTP server versions 2.4.37 and prior, by sending request bodies in a slow loris way to plain resources, the h2 stream for that request unnecessarily occupied a server thread cleaning up that incoming data. This affects only HTTP/2 (mod_http2) connections.

  10. MediumCVSS 5.9 EPSS 51.0%

    In Apache HTTP Server 2.4.17 to 2.4.34, by sending continuous, large SETTINGS frames a client can occupy a connection, server thread and CPU time without any connection timeout coming to effect. This affects only HTTP/2 connections. A possible mitigation is to not enable the h2 p...

  11. MediumCVSS 6.1 EPSS 19.9%

    Possible CRLF injection allowing HTTP response splitting attacks for sites which use mod_userdir. This issue was mitigated by changes made in 2.4.25 and 2.2.32 which prohibit CR or LF injection into the "Location" or other outbound header key or value. Fixed in Apache HTTP Server...

  12. MediumCVSS 6.5 EPSS 8.1%

    A regression was found in the Red Hat Enterprise Linux 6.9 version of httpd 2.2.15-60, causing comments in the "Allow" and "Deny" configuration lines to be parsed incorrectly. A web administrator could unintentionally allow any client to access a restricted HTTP resource.

  13. HighCVSS 7.5 EPSS 17.0%

    By specially crafting HTTP/2 requests, workers would be allocated 60 seconds longer than necessary, leading to worker exhaustion and a denial of service. Fixed in Apache HTTP Server 2.4.34 (Affected 2.4.18-2.4.30,2.4.33).

  14. CriticalCVSS 9.8 EPSS 15.8%

    In Apache httpd 2.2.0 to 2.4.29, 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 coul...

  15. HighCVSS 7.5 EPSS 69.8%

    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. The vulnera...

  16. MediumCVSS 5.9 EPSS 12.9%

    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 configurati...

  17. MediumCVSS 5.9 EPSS 14.5%

    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 l...

  18. MediumCVSS 5.3 EPSS 9.7%

    In Apache httpd 2.4.0 to 2.4.29, 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_se...

  19. HighCVSS 8.1 EPSS 86.2%

    In Apache httpd 2.4.0 to 2.4.29, 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 are externally bloc...

  20. HighCVSS 7.5 EPSS 17.5%

    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...

Sources: CVE.org, NVD, CISA KEV, FIRST EPSS, OSV and public exploit-reference metadata. Product matching comes from the published CVE records. A proof-of-concept means public code exists; it is not evidence of exploitation.