Debian dla-4270 : apache2 - security update

critical Nessus Plugin ID 249166

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Synopsis

The remote Debian host is missing one or more security-related updates.

Description

The remote Debian 11 host has packages installed that are affected by multiple vulnerabilities as referenced in the dla-4270 advisory.

- ------------------------------------------------------------------------- Debian LTS Advisory DLA-4270-1 [email protected] https://www.debian.org/lts/security/ Bastien Roucaris August 12, 2025 https://wiki.debian.org/LTS
- -------------------------------------------------------------------------

Package : apache2 Version : 2.4.65-1~deb11u1 CVE ID : CVE-2024-42516 CVE-2024-43204 CVE-2024-43394 CVE-2024-47252 CVE-2025-23048 CVE-2025-49630 CVE-2025-49812 CVE-2025-53020 CVE-2025-54090

Multiple vulnerabilities have been addressed in Apache, a widely used web server.

Please note that the fix for CVE-2025-23048, included in this DLA, may cause some SSL-enabled websites to encounter the error AH02032.
Additional details are provided at the end of this advisory.

CVE-2024-42516

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

CVE-2024-43204

A SSRF (Server Side Request Forgery) was found in Apache HTTP Server with mod_proxy loaded allows an attacker to send outbound proxy requests to a URL controlled by the attacker.
This attack requires an unlikely configuration where mod_headers is configured to modify the Content-Type request or response header with a value provided in the HTTP request

CVE-2024-43394

A 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.

CVE-2024-47252

Insufficient escaping of user-supplied data in mod_ssl allows an untrusted SSL/TLS client to insert escape characters into log files in some configurations. In a logging configuration where CustomLog is used with %{varname}x or %{varname}c to log variables provided by mod_ssl such as SSL_TLS_SNI, no escaping is performed by either mod_log_config or mod_ssl and unsanitized data provided by the client may appear in log files.

CVE-2025-23048

An access control bypass by trusted clients is possible using TLS 1.3 session resumption. Configurations are affected when mod_ssl is configured for multiple virtual hosts, with each restricted to a different set of trusted client certificates (for example with a different SSLCACertificateFile/Path setting).
In such a case, a client trusted to access one virtual host may be able to access another virtual host, if SSLStrictSNIVHostCheck is not enabled in either virtual host.

CVE-2025-49630

In certain proxy configurations, a denial of service attack against Apache HTTP Server can be triggered by untrusted clients causing an assertion in mod_proxy_http2. Configurations affected are a reverse proxy is configured for an HTTP/2 backend, with ProxyPreserveHost set to on.

CVE-2025-49812

In some mod_ssl configurations on Apache HTTP server, an HTTP desynchronisation attack allows a man-in-the-middle attacker to hijack an HTTP session via a TLS upgrade. Only configurations using SSLEngine optional to enable TLS upgrades are affected.
Support for TLS upgrade was removed.

CVE-2025-53020

A late Release of Memory after Effective Lifetime vulnerability was found in Apache HTTP Server.

CVE-2025-54090

A bug in Apache HTTP Server 2.4.64 results in all RewriteCond expr ... tests evaluating as true

For Debian 11 bullseye, these problems have been fixed in version 2.4.65-1~deb11u1.

Note that following the resolution of CVE-2025-23048, some SSL-enabled websites may begin encountering the error (AH02032):

Misdirected Request:
The client needs a new connection for this request as the requested host name does not match the Server Name Indication (SNI) in use for this connection.

This behavior is particularly noticeable with AWS Application Load Balancers. Although they support intelligent SNI handling, they do not (as of this writing) relay SNI data to the target server, resulting in failed connections when hostnames don??t align.

Without an SNI provided by the client, there is nothing httpd can do to determine which vhost/configuration should be used to provide the correct certificate (and TLS authentication eventually) whenever multiple vhosts listen on the same IP:port.

That's because reading the HTTP Host header necessarily has to happen after the TLS handshake/auth/decryption (and later renegotiation is not an option with TLSv1.3).

So those connections fall back to the first vhost declared on the IP:port for the TLS handshake part, and if the request Host header finally matches a different vhost with a different TLS configuration it's rejected with AH02032.

Before 2.4.64 the check was not accurate and would allow that, with security implications.

As a workaround, you may (after a risk analysis) generate a wildcard certificate. If you??re managing multiple domains, consolidate them into a single certificate by including each wildcard domain as an alias. Then, update the Apache configuration to reference this unified certificate.

Another possible workaround is to configure each virtual host to listen on a separate port. This approach avoids SNI-related issues by ensuring that each vhost is uniquely addressed through its own connection endpoint, thereby allowing distinct TLS configurations without ambiguity.

This error may also stem from a misconfigured HAProxy setup.
In such cases, enabling dynamic SNI handling on HAProxy might be necessary to ensure that the correct hostname is passed through during the TLS handshake. After risk analysis, it could be done by using sni req.hdr(Host) directive.

We recommend that you upgrade your apache2 packages.

For the detailed security status of apache2 please refer to its security tracker page at:
https://security-tracker.debian.org/tracker/apache2

Further information about Debian LTS security advisories, how to apply these updates to your system and frequently asked questions can be found at: https://wiki.debian.org/LTS

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

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

Solution

Upgrade the apache2 packages.

Plugin Details

Severity: Critical

ID: 249166

File Name: debian_DLA-4270.nasl

Version: 1.1

Type: local

Agent: unix

Family: Debian Local Security Checks

Published: 8/12/2025

Updated: 8/12/2025

Supported Sensors: Frictionless Assessment Agent, Nessus Agent, Agentless Assessment, Continuous Assessment, Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 6.0

CVSS v2

Risk Factor: High

Base Score: 9.4

Temporal Score: 7

Vector: CVSS2#AV:N/AC:L/Au:N/C:C/I:C/A:N

CVSS Score Source: CVE-2025-23048

CVSS v3

Risk Factor: Critical

Base Score: 9.1

Temporal Score: 7.9

Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

Temporal Vector: CVSS:3.0/E:U/RL:O/RC:C

Vulnerability Information

CPE: cpe:/o:debian:debian_linux:11.0, p-cpe:/a:debian:debian_linux:apache2-bin, p-cpe:/a:debian:debian_linux:libapache2-mod-md, p-cpe:/a:debian:debian_linux:libapache2-mod-proxy-uwsgi, p-cpe:/a:debian:debian_linux:apache2-doc, p-cpe:/a:debian:debian_linux:apache2-suexec-custom, p-cpe:/a:debian:debian_linux:apache2, p-cpe:/a:debian:debian_linux:apache2-dev, p-cpe:/a:debian:debian_linux:apache2-data, p-cpe:/a:debian:debian_linux:apache2-suexec-pristine, p-cpe:/a:debian:debian_linux:apache2-utils, p-cpe:/a:debian:debian_linux:apache2-ssl-dev

Required KB Items: Host/local_checks_enabled, Host/Debian/release, Host/Debian/dpkg-l

Exploit Ease: No known exploits are available

Patch Publication Date: 8/12/2025

Vulnerability Publication Date: 7/8/2025

Reference Information

CVE: CVE-2024-42516, CVE-2024-43204, CVE-2024-43394, CVE-2024-47252, CVE-2025-23048, CVE-2025-49630, CVE-2025-49812, CVE-2025-53020, CVE-2025-54090

IAVA: 2025-A-0508-S, 2025-A-0547

Detections

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