The remote CentOS Linux 8 host has packages installed that are affected by multiple vulnerabilities as referenced in the CESA-2020:4751 advisory.

  - httpd: mod_http2: DoS via slow, unneeded request bodies (CVE-2018-17189)

  - httpd: mod_http2: read-after-free on a string compare (CVE-2019-0196)

  - httpd: mod_http2: possible crash on late upgrade (CVE-2019-0197)

  - httpd: memory corruption on early pushes (CVE-2019-10081)

  - httpd: read-after-free in h2 connection shutdown (CVE-2019-10082)

  - httpd: limited cross-site scripting in mod_proxy error page (CVE-2019-10092)

  - httpd: null-pointer dereference in mod_remoteip (CVE-2019-10097)

  - httpd: mod_rewrite potential open redirect (CVE-2019-10098)

  - httpd: mod_rewrite configurations vulnerable to open redirect (CVE-2020-1927)

  - httpd: mod_proxy_ftp use of uninitialized value (CVE-2020-1934)

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The remote Alibaba Cloud Linux 3 host has packages installed that are affected by multiple vulnerabilities as referenced in the ALINUX3-SA-2022:0017 advisory.

    Package updates are available for Alibaba Cloud Linux 3 that fix the following vulnerabilities:

    CVE-2019-0190:
    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 OpenSSL version 1.1.1 or later, due to an     interaction in changes to handling of renegotiation attempts.

    CVE-2019-0196:
    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.

    CVE-2019-0197:
    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 and crash. Server that never enabled     the h2 protocol or that only enabled it for https: and did not set H2Upgrade on are unaffected by this     issue.

    CVE-2019-0211:
    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 process (usually root) by     manipulating the scoreboard. Non-Unix systems are not affected.

    CVE-2019-0215:
    In Apache HTTP Server 2.4 releases 2.4.37 and 2.4.38, a bug in mod_ssl when using per-location client     certificate verification with TLSv1.3 allowed a client to bypass configured access control restrictions.

    CVE-2019-0217:
    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.

    CVE-2019-0220:
    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 servers processing will implicitly     collapse them.

    CVE-2019-10082:
    In Apache HTTP Server 2.4.18-2.4.39, using fuzzed network input, the http/2 session handling could be made     to read memory after being freed, during connection shutdown.

    CVE-2019-10092:
    In Apache HTTP Server 2.4.0-2.4.39, a limited cross-site scripting issue was reported affecting the     mod_proxy error page. An attacker could cause the link on the error page to be malformed and instead point     to a page of their choice. This would only be exploitable where a server was set up with proxying enabled     but was misconfigured in such a way that the Proxy Error page was displayed.

    CVE-2019-10097:
    In Apache HTTP Server 2.4.32-2.4.39, when mod_remoteip was configured to use a trusted intermediary proxy     server using the PROXY protocol, a specially crafted PROXY header could trigger a stack buffer overflow     or NULL pointer deference. This vulnerability could only be triggered by a trusted proxy and not by     untrusted HTTP clients.

    CVE-2019-10098:
    In Apache HTTP server 2.4.0 to 2.4.39, Redirects configured with mod_rewrite that were intended to be     self-referential might be fooled by encoded newlines and redirect instead to an unexpected URL within the     request URL.

    CVE-2019-9511:
    Some HTTP/2 implementations are vulnerable to window size manipulation and stream prioritization     manipulation, potentially leading to a denial of service. The attacker requests a large amount of data     from a specified resource over multiple streams. They manipulate window size and stream priority to force     the server to queue the data in 1-byte chunks. Depending on how efficiently this data is queued, this can     consume excess CPU, memory, or both.

    CVE-2019-9516:
    Some HTTP/2 implementations are vulnerable to a header leak, potentially leading to a denial of service.
    The attacker sends a stream of headers with a 0-length header name and 0-length header value, optionally     Huffman encoded into 1-byte or greater headers. Some implementations allocate memory for these headers and     keep the allocation alive until the session dies. This can consume excess memory.

    CVE-2019-9517:
    Some HTTP/2 implementations are vulnerable to unconstrained interal data buffering, potentially leading to     a denial of service. The attacker opens the HTTP/2 window so the peer can send without constraint;
    however, they leave the TCP window closed so the peer cannot actually write (many of) the bytes on the     wire. The attacker then sends a stream of requests for a large response object. Depending on how the     servers queue the responses, this can consume excess memory, CPU, or both.

    CVE-2020-11984:
    Apache HTTP server 2.4.32 to 2.4.44 mod_proxy_uwsgi info disclosure and possible RCE

    CVE-2020-11993:
    Apache HTTP Server versions 2.4.20 to 2.4.43 When trace/debug was enabled for the HTTP/2 module and on     certain traffic edge patterns, logging statements were made on the wrong connection, causing concurrent     use of memory pools. Configuring the LogLevel of mod_http2 above info will mitigate this vulnerability     for unpatched servers.

    CVE-2020-1927:
    In Apache HTTP Server 2.4.0 to 2.4.41, redirects configured with mod_rewrite that were intended to be     self-referential might be fooled by encoded newlines and redirect instead to an an unexpected URL within     the request URL.

    CVE-2020-1934:
    In Apache HTTP Server 2.4.0 to 2.4.41, mod_proxy_ftp may use uninitialized memory when proxying to a     malicious FTP server.

    CVE-2020-9490:
    Apache HTTP Server versions 2.4.20 to 2.4.43. A specially crafted value for the 'Cache-Digest' header in a     HTTP/2 request would result in a crash when the server actually tries to HTTP/2 PUSH a resource     afterwards. Configuring the HTTP/2 feature via H2Push off will mitigate this vulnerability for unpatched     servers.

    CVE-2021-26690:
    Apache HTTP Server versions 2.4.0 to 2.4.46 A specially crafted Cookie header handled by mod_session can     cause a NULL pointer dereference and crash, leading to a possible Denial Of Service

    CVE-2021-30641:
    Apache HTTP Server versions 2.4.39 to 2.4.46 Unexpected matching behavior with 'MergeSlashes OFF'

    CVE-2021-34798:
    Malformed requests may cause the server to dereference a NULL pointer. This issue affects Apache HTTP     Server 2.4.48 and earlier.

    CVE-2021-39275:
    ap_escape_quotes() may write beyond the end of a buffer when given malicious input. No included modules     pass untrusted data to these functions, but third-party / external modules may. This issue affects Apache     HTTP Server 2.4.48 and earlier.

    CVE-2021-44790:
    A carefully crafted request body can cause a buffer overflow in the mod_lua multipart parser     (r:parsebody() called from Lua scripts). The Apache httpd team is not aware of an exploit for the     vulnerabilty though it might be possible to craft one. This issue affects Apache HTTP Server 2.4.51 and     earlier.

Tenable has extracted the preceding description block directly from the Alibaba Cloud Linux security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The Rocky Linux 8.6 host has a package installed that is affected by multiple vulnerabilities as referenced in the CIQ ciqsa-2026_1605 advisory.

    This advisory aggregates security fixes for the mod_http2 SRPM in CIQ LTS 8.6. It addresses 14 CVEs:
    CVE-2023-44487, CVE-2019-9516, CVE-2019-9511, CVE-2019-9517, CVE-2020-11993, and 9 more.

Tenable has extracted the preceding description block directly from the CIQ security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

ID	Name	Product	Family	Published	Updated	Severity
145821	CentOS 8 : httpd:2.4 (CESA-2020:4751)	Nessus	CentOS Local Security Checks	2/1/2021	2/8/2023	critical
236421	Alibaba Cloud Linux 3 : 0017: httpd:2.4 (ALINUX3-SA-2022:0017)	Nessus	Alibaba Cloud Linux Local Security Checks	5/14/2025	5/15/2025	critical
364632	Rocky Linux 8.6 [CIQ] Security Update: mod_http2 Multiple Vulnerabilities (ciqsa-2026_1605)	Nessus	Rocky Linux Local Security Checks	10/12/2026	10/13/2026	medium

Detections

Analytics

Plugins Search

critical

critical

medium