by Cesar Navas
November 2, 2022
On December 9, 2021, researchers published proof-of-concept (PoC) exploit code for a critical vulnerability in Apache Log4j, a Java logging library used by a number of applications and services. This vulnerability, identified as CVE-2021-44228, is a Remote Code Execution (RCE) vulnerability in Apache Log4j. This dashboard is designed to help organizations determine what assets may contain vulnerabilities susceptible to the Apache Log4j exploit.
The Log4j vulnerability impacts a number of services and applications used widely across the internet, and is actively being exploited with multiple proofs of concept on GitHub.
According to the published CVE, all Apache Log4j versions 2.14.1 or less are vulnerable. An unauthenticated remote attacker could exploit this flaw by sending a specially crafted request to a server running a vulnerable version of Log4j. The crafted request uses a Java Naming and Directory Interface (JNDI) injection via a variety of services including:
- Lightweight Directory Access Protocol (LDAP)
- Secure LDAP (LDAPS)
- Remote Method Invocation (RMI)
- Domain Name Service (DNS)
Successful exploitation could lead to RCE. In Log4j version 2.15.0 and higher, this behavior is disabled by default.
The solution is complex because Log4j version 2.15.0 requires Java 8 to be installed. Therefore organizations using older versions of Java will be required to upgrade Java before applying the patched version. Log4j is also used by a number of cloud service providers, making the full scope of this vulnerability unknown at this time. A list of Tenable plugins to identify this vulnerability will appear here as the plugins are released.
Tenable has provided the log4shell Critical Vulnerability dashboard to assist organizations with the identification of whether Log4j is installed and currently running on any previously scanned assets. Because the update also requires Java 8 to be installed as a prerequisite, information on Java installations is also provided. This information can be used by organizations to determine the scope of their mitigation efforts. Tenable Research has also released a blog post that outlines additional steps that organizations can take to protect themselves from this vulnerability.
The Security Response Team (SRT) in Tenable Research works to dig into technical details and test proof-of-concept attacks, when available, to ensure customers are fully informed of the risks. The SRT also provides breakdowns for the latest vulnerabilities in the Tenable Blog. Tenable Research has released over 165,000 plugins and leads the industry on CVE coverage. Tenable's SRT team continuously works to help organizations prioritize and create remediation plans for the new threats, which often leave very little time for reflection.
Security leaders need to SEE everything, PREDICT what matters most and ACT to address cyber risk and effectively align cybersecurity initiatives with business objectives. Tenable.io discovers and analyzes assets continuously to provide an accurate and unified view of an organization’s security posture. The requirements for this widget are: Tenable.io Vulnerability Management (Nessus) and Tenable Web Application Security (WAS).
Widgets
log4shell - Log4j Concerns: This widget alerts organizations to potential concerns regarding the Log4j vulnerability. Displayed are the vulnerabilities that are directly associated with the log4shell CVEs (CVE-2021-44228, CVE-2021-44832, CVE-2021-45046, CVE-2021-4104, and CVE-2021-45105) and Log4j installations. Since installing Java v8 is also a requirement to address this exploit, a row is presented of vulnerabilities that are associated with Java, JRE, and JDK. Identifying where Log4j and Java are installed in the organization enables security teams to prioritize remediation. The requirements for this widget are: Tenable.io Vulnerability Management (Nessus, NNM).
log4shell - High Risk Vulnerabilities: Apache, Log4j, and Java: This widget lists the high-risk vulnerabilities related to Apache, Log4j, and Java software as well as services detected in the environment. Relevant vulnerabilities with a critical and high severity level are displayed that present the highest level of risk to the organization. The plugin name, severity, and plugin ID are listed for each vulnerability. Security teams can use this widget to identify and remediate the highest risk vulnerabilities in Apache, Log4j, and Java software. The requirement for this widget is: Tenable.io Vulnerability Management (Nessus).
BOD 22-01 - DHS Tracked Known Exploited Vulnerabilities: This widget displays vulnerability status counts for DHS tracked known vulnerabilities derived from the CISA Known Exploited Vulnerabilities Catalog. The widget uses the CVE filter to exactly match the CVEs included in the CISA Known Exploited Vulnerabilities Catalog and sorts the results in rows by: past due vulnerabilities; vulnerabilities due Nov/Dec 2021, and vulnerabilities due May/June 2022. The Vulnerabilities Identified column displays the active vulnerability count and is followed by the fixed vulnerability count column. The requirements for this widget are: Tenable.io Vulnerability Management (Nessus, NNM).
Prioritize Hosts - Top Hosts with Java Vulnerabilities: This widget displays the top 100 hosts on the network that have detected Java vulnerabilities. A count of vulnerabilities is displayed for each host, sorted from highest to lowest number of vulnerabilities. In the widget filter, the Plugin Name is set to the "java" wildcard to locate plugins that report Java vulnerabilities. This widget can be copied and other keywords used to detect other types of vulnerabilities. Some keyword suggestions are "adobe," "unsupported," "default," "malicious process," and "xss.” The requirement for this widget is: Tenable.io Vulnerability Management (Nessus).
WAS Detected Applications Vulnerable to Log4Shell: This widget presents a list of assets detected by the Tenable WAS scanner that are vulnerable to log4shell exploits. The table uses the Apache Log4j Remote Code Execution (Log4Shell) plugin to identify vulnerable applications. Plugin 113075 is available for WAS users, both in Tenable.io and Tenable Core + WAS. - The plugin, delivered in WAS v1.21.2, is capable of parsing though web application surfaces for evidence of the vulnerability. Plugin 113076 is used in conjunction with plugin 113075 to detect files possibly related to installation files. Detected files require an immediate review to verify the presence of Apache Log4j and determine if it is affected by the critical vulnerability described in CVE-2021-44228. If confirmed, update Log4j to version 2.15.0 or later or apply the vendor-recommended mitigations. Ensure that proper restrictions are in place on the detected file, or remove it if not required. The requirements for this widget are: Tenable.io Vulnerability Management (Nessus) and Tenable Web Application Security (WAS).