What is Log4j vulnerability explained
The Log4j 2 library controls how applications log strings of code and information. The vulnerability enables an attacker to gain control over a string and trick the application into requesting and executing malicious code under the attacker's control.
What is the Log4Shell vulnerability
Log4Shell (CVE-2021-44228, CVE-2021-45046 and CVE-2021-45105) is a remote code execution (RCE) vulnerability that enables malicious actors to execute arbitrary Java code, taking control of a target server.
What is log4 in cyber security
Log4j is used by developers to keep track of what happens in their software applications or online services. It's basically a huge journal of the activity of a system or application. This activity is called 'logging' and it's used by developers to keep an eye out for problems for users.
What is Log4j or Log4j2 vulnerability
Background: The Apache Log4j 2 utility is a commonly used component for logging requests. On December 9, 2021, a vulnerability was reported that could allow a system running Apache Log4j 2 version 2.15 or below to be compromised and allow an attacker to execute arbitrary code.
Why is Log4j important
Log4j is one of the most widely used tools to collect information across computers systems, apps, networks, websites, etc. It has been downloaded millions of times. Also, it is used by other frameworks, for example, Elasticsearch, Kafka, etc.
What is the impact of Log4j
The Log4j exploit, also known as the Log4Shell vulnerability, allows threat actors to take control of web-facing servers by feeding them a malicious text string.
Why did Log4j happen
So, how did it happen Essentially, this vulnerability is the combination of a design flaw and bad habits, according to the experts I spoke to for this post. The cybersecurity industry has dubbed this exploit Log4J, naming it after the Java logging framework that is the source of the problem.
Is Log4j a threat
A critical security flaw in the Log4j framework is allowing cybercriminals to compromise vulnerable systems with just a single malicious code injection. The vulnerability is associated with the user activity logger known as Log4J – a logging library freely distributed by the Apache Software Foundation.
Why is Log4j so popular
The first Java Development Kit (JDK) did not include logging APIs, so that's why java logging libraries gain success, including Log4j. Log4j is one of the most widely used tools to collect information across computers systems, apps, networks, websites, etc.
What is Log4j2 vulnerabilities
Log4j2 allows Lookup expressions in the data being logged exposing the JNDI vulnerability, as well as other problems, to be exploited by end users whose input is being logged. CVE-2021-44228. Remote Code Execution. Severity. Critical.
How does Log4j affect me
Although this is a secure functionality, the Log4j flaw allows an attacker to input their own JNDI lookups, where they then direct the server to their fake LDAP server. From here, the attacker now has control of the remote system and can execute malware, exfiltrate sensitive information like passwords, and more.
What is the impact of Log4j vulnerability
The Apache Log4j vulnerabilities, also known as “Log4Shell”, enable an attacker to conduct remote code execution by exploiting the JNDI lookups feature that is not secured within the login library of log4j. The attackers only require a malicious request with a formatted string to be recognized by the Log4j libraries.
What can hackers do with Log4j vulnerability
The Log4j vulnerability allows hackers to execute code remotely on target systems and computers. It's a high-profile security vulnerability whose severity score is ten out of ten. Attackers were able to send server commands that vulnerable servers would execute.
How much damage did Log4j cause
As per Cybersecurity firm Check Point, over 800,000 exploitation attempts were detected in the first 72 hours after log4j issue became public. Experts predict that the Log4j security vulnerability could impact the entire internet. The widespread impact of the vulnerability is so large that it may take years to fix.
Who attacked Log4j
Attacks exploiting the Log4j vulnerability appear to have been limited to Minecraft servers until the issue was made public by Apache on December 9, 2021.
Who has been hacked by Log4j
Over a hundred vendors confirmed to be affected including: Microsoft, Amazon Web Services, Netflix and Oracle, and experts say that the flaw has gone unnoticed since 2013.
What damage is done by Log4j
The vulnerability discovered in the Log4j code would allow hackers to execute any software code on the target computer. The government report emphasized that while the vulnerability had been extremely disruptive that there was little evidence of malicious damage caused by it.
Is Log4j vulnerability bad
Although this is a secure functionality, the Log4j flaw allows an attacker to input their own JNDI lookups, where they then direct the server to their fake LDAP server. From here, the attacker now has control of the remote system and can execute malware, exfiltrate sensitive information like passwords, and more.
Who is at risk for Log4j
What Specific Devices are at Risk According to ZDNet, “Any device that's exposed to the internet is at risk if it's running Apache Log4J, versions 2.0 to 2.14. 1." This affects both IT and Operational Technology (OT) networks.
What is Log4j cyber threats
Continued Log4j Attack Incidents
From Iran, cyber threat actors took advantage of the Log4Shell vulnerability in an unpatched VMware Horizon server, installed crypto mining software, moved laterally to the domain controller, compromised credentials and implanted reverse proxies on several hosts to maintain persistence.
Why was Log4j so bad
Although this is a secure functionality, the Log4j flaw allows an attacker to input their own JNDI lookups, where they then direct the server to their fake LDAP server. From here, the attacker now has control of the remote system and can execute malware, exfiltrate sensitive information like passwords, and more.
Is Log4j still a threat
Log4j remains a threat in 2023
The highest concentration of critical findings linked to Log4j were found within the first 48 hours of the vulnerability becoming known. At the time, findings often originated in the core of an application and later findings migrated to the dependences those applications rely on.
How do I know if I am vulnerable to Log4j
We also use a log inspection rule to detect the vulnerability. The log inspection rule 1011241 – Apache Log4j Remote Code Execution Vulnerability (CVE-2021-44228) looks for JNDI payloads in the access logs, with the default path being /var/log/*/access. log.
How bad is the Log4j vulnerability
Although this is a secure functionality, the Log4j flaw allows an attacker to input their own JNDI lookups, where they then direct the server to their fake LDAP server. From here, the attacker now has control of the remote system and can execute malware, exfiltrate sensitive information like passwords, and more.
What did Log4j affect
The Log4j exploit, also known as the Log4Shell vulnerability, allows threat actors to take control of web-facing servers by feeding them a malicious text string.
