Debian DLA-2209-1 : tomcat8 security update

critical Nessus Plugin ID 136951
New! Plugin Severity Now Using CVSS v3

The calculated severity for Plugins has been updated to use CVSS v3 by default. Plugins that do not have a CVSS v3 score will fall back to CVSS v2 for calculating severity. Severity display preferences can be toggled in the settings dropdown.

Synopsis

The remote Debian host is missing a security update.

Description

Several security vulnerabilities have been discovered in the Tomcat servlet and JSP engine.

WARNING: The fix for CVE-2020-1938 may disrupt services that rely on a working AJP configuration. The option secretRequired defaults to true now. You should define a secret in your server.xml or you can revert back by setting secretRequired to false.

CVE-2019-17563

When using FORM authentication with Apache Tomcat there was a narrow window where an attacker could perform a session fixation attack. The window was considered too narrow for an exploit to be practical but, erring on the side of caution, this issue has been treated as a security vulnerability.

CVE-2020-1935

In Apache Tomcat the HTTP header parsing code used an approach to end-of-line parsing that allowed some invalid HTTP headers to be parsed as valid. This led to a possibility of HTTP Request Smuggling if Tomcat was located behind a reverse proxy that incorrectly handled the invalid Transfer-Encoding header in a particular manner. Such a reverse proxy is considered unlikely.

CVE-2020-1938

When using the Apache JServ Protocol (AJP), care must be taken when trusting incoming connections to Apache Tomcat. Tomcat treats AJP connections as having higher trust than, for example, a similar HTTP connection. If such connections are available to an attacker, they can be exploited in ways that may be surprising. Previously Tomcat shipped with an AJP Connector enabled by default that listened on all configured IP addresses. It was expected (and recommended in the security guide) that this Connector would be disabled if not required.
. Note that Debian already disabled the AJP connector by default.
Mitigation is only required if the AJP port was made accessible to untrusted users.

CVE-2020-9484

When using Apache Tomcat and an attacker is able to control the contents and name of a file on the server; and b) the server is configured to use the PersistenceManager with a FileStore; and c) the PersistenceManager is configured with sessionAttributeValueClassNameFilter='null' (the default unless a SecurityManager is used) or a sufficiently lax filter to allow the attacker provided object to be deserialized; and d) the attacker knows the relative file path from the storage location used by FileStore to the file the attacker has control over; then, using a specifically crafted request, the attacker will be able to trigger remote code execution via deserialization of the file under their control. Note that all of conditions a) to d) must be true for the attack to succeed.

For Debian 8 'Jessie', these problems have been fixed in version 8.0.14-1+deb8u17.

We recommend that you upgrade your tomcat8 packages.

NOTE: Tenable Network Security has extracted the preceding description block directly from the DLA security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

Solution

Upgrade the affected packages.

See Also

https://lists.debian.org/debian-lts-announce/2020/05/msg00026.html

https://packages.debian.org/source/jessie/tomcat8

Plugin Details

Severity: Critical

ID: 136951

File Name: debian_DLA-2209.nasl

Version: 1.7

Type: local

Agent: unix

Published: 5/29/2020

Updated: 1/11/2021

Dependencies: ssh_get_info.nasl

Risk Information

VPR

Risk Factor: Critical

Score: 9.5

CVSS v2

Risk Factor: High

Base Score: 7.5

Temporal Score: 5.9

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

Temporal Vector: E:POC/RL:OF/RC:C

CVSS v3

Risk Factor: Critical

Base Score: 9.8

Temporal Score: 8.8

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

Temporal Vector: E:P/RL:O/RC:C

Vulnerability Information

CPE: p-cpe:/a:debian:debian_linux:libservlet3.1-java, p-cpe:/a:debian:debian_linux:libservlet3.1-java-doc, p-cpe:/a:debian:debian_linux:libtomcat8-java, p-cpe:/a:debian:debian_linux:tomcat8, p-cpe:/a:debian:debian_linux:tomcat8-admin, p-cpe:/a:debian:debian_linux:tomcat8-common, p-cpe:/a:debian:debian_linux:tomcat8-docs, p-cpe:/a:debian:debian_linux:tomcat8-examples, p-cpe:/a:debian:debian_linux:tomcat8-user, cpe:/o:debian:debian_linux:8.0

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

Exploit Available: true

Exploit Ease: Exploits are available

Patch Publication Date: 5/28/2020

Vulnerability Publication Date: 12/23/2019

Reference Information

CVE: CVE-2019-17563, CVE-2020-1935, CVE-2020-1938, CVE-2020-9484

IAVA: 2020-A-0225-S