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Ubuntu 18.04 LTS / 20.04 LTS : Apache HTTP Server vulnerabilities (USN-4994-1)

critical Nessus Plugin ID 150940

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Synopsis

The remote Ubuntu host is missing one or more security updates.

Description

The remote Ubuntu 18.04 LTS / 20.04 LTS / 20.10 / 21.04 host has packages installed that are affected by multiple vulnerabilities as referenced in the USN-4994-1 advisory.

 - Apache HTTP Server versions 2.4.41 to 2.4.46 mod_proxy_http can be made to crash (NULL pointer dereference) with specially crafted requests using both Content-Length and Transfer-Encoding headers, leading to a Denial of Service (CVE-2020-13950)

 - Apache HTTP Server versions 2.4.0 to 2.4.46 A specially crafted Digest nonce can cause a stack overflow in mod_auth_digest. There is no report of this overflow being exploitable, nor the Apache HTTP Server team could create one, though some particular compiler and/or compilation option might make it possible, with limited consequences anyway due to the size (a single byte) and the value (zero byte) of the overflow (CVE-2020-35452)

 - 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-2021-26690)

 - In Apache HTTP Server versions 2.4.0 to 2.4.46 a specially crafted SessionHeader sent by an origin server could cause a heap overflow (CVE-2021-26691)

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

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

Solution

Update the affected packages.

See Also

https://ubuntu.com/security/notices/USN-4994-1

Plugin Details

Severity: Critical

ID: 150940

File Name: ubuntu_USN-4994-1.nasl

Version: 1.6

Type: local

Agent: unix

Published: 6/21/2021

Updated: 10/16/2023

Supported Sensors: Frictionless Assessment AWS, Frictionless Assessment Azure, Frictionless Assessment Agent, Nessus Agent, Agentless Assessment, Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 6.7

CVSS v2

Risk Factor: High

Base Score: 7.5

Temporal Score: 5.5

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

CVSS Score Source: CVE-2021-26691

CVSS v3

Risk Factor: Critical

Base Score: 9.8

Temporal Score: 8.5

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

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

Vulnerability Information

CPE: cpe:/o:canonical:ubuntu_linux:18.04:-:lts, cpe:/o:canonical:ubuntu_linux:20.04:-:lts, p-cpe:/a:canonical:ubuntu_linux:apache2, p-cpe:/a:canonical:ubuntu_linux:apache2-bin, p-cpe:/a:canonical:ubuntu_linux:apache2-data, p-cpe:/a:canonical:ubuntu_linux:apache2-dev, p-cpe:/a:canonical:ubuntu_linux:apache2-ssl-dev, p-cpe:/a:canonical:ubuntu_linux:apache2-suexec-custom, p-cpe:/a:canonical:ubuntu_linux:apache2-suexec-pristine, p-cpe:/a:canonical:ubuntu_linux:apache2-utils, p-cpe:/a:canonical:ubuntu_linux:libapache2-mod-md, p-cpe:/a:canonical:ubuntu_linux:libapache2-mod-proxy-uwsgi

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

Exploit Ease: No known exploits are available

Patch Publication Date: 6/21/2021

Vulnerability Publication Date: 6/1/2021

Reference Information

CVE: CVE-2020-13950, CVE-2020-35452, CVE-2021-26690, CVE-2021-26691, CVE-2021-30641

IAVA: 2021-A-0259-S

USN: 4994-1