CISA, FBI and NSA Publish Joint Advisory and Scanner for Log4j Vulnerabilities
Vulnerabilities mentionedAll →
| CVE | Vulnerability | CVSS | EPSS | Flags | Affected | Exposure | Published |
|---|---|---|---|---|---|---|---|
| CVE-2021-44790 +1 in the same advisory: …44224 | A carefully crafted request body can cause a buffer overflow in the mod_lua multipart parser (r:parsebody() called from Lua scripts). A carefully crafted request body can cause a buffer overflow in the mod_lua multipart parser (r:parsebody() called from Lua scripts). The Apache httpd team is not aware of an exploit for the vulnerabilty though it might be possible to craft one. This issue affects Apache HTTP Server 2.4.51 and earlier. NVD description · AI analysis pending | 9.8 group max | 97% | PoC |
| — | |
| CVE-2021-44228 | JNDI Injection Remote Code Execution in Apache Log4j2 (Log4Shell) Apache Log4j2, an extremely widely used Java logging library, fails to protect its JNDI lookup feature against attacker-controlled JNDI-related endpoints (CWE-20, CWE-502), so crafted text processed by the logger causes the Java runtime to fetch and load attacker-supplied objects, leading to remote code execution. The flaw is triggered whenever attacker-controlled input reaches the logging API and is parsed for JNDI lookups, a pattern common in web servers and enterprise Java applications that log user-supplied fields such as headers or form values. Successful exploitation yields arbitrary code execution under the privileges of the affected application, giving attackers a foothold for lateral movement, data theft, and ransomware deployment. Any Java application or product that ships or bundles an affected Apache Log4j2 release is exposed, making this one of the most broadly deployed vulnerabilities ever disclosed. Exploitation is confirmed in the wild: CISA added it to the Known Exploited Vulnerabilities catalog on 2021-12-10 with known ransomware use, and EPSS assigns a 100% probability of exploitation within 30 days. Do: Inventory all Java applications and dependencies for Apache Log4j2 and apply the vendor's patched updates, or remove affected assets from the network, as required by CISA's KEV catalog. Where updates are not yet available, use the temporary mitigations in CISA's ED-22-02 recommended-mitigation guidance, such as disabling message lookups, only until patches are applied. Prioritize internet-facing and business-critical systems and hunt for exploitation activity given known ransomware use. | 10.0 | 100% | KEV ransomware PoC ×9 |
| masshundreds of millions of Java applications/devices, with hundreds of thousands of internet-exposed services | |
| CVE-2021-45046 | Remote Code Execution in Apache Log4j2 via Incomplete Log4Shell Fix CVE-2021-45046 is a remote code execution and information disclosure flaw in Apache Log4j2 (CWE-917) that resulted from an incomplete fix to CVE-2021-44228 (Log4Shell), leaving the Thread Context Lookup Pattern vulnerable in certain non-default configurations. It is triggered when an application logs attacker-controlled data using layouts or patterns that perform Thread Context (MDC) lookups, allowing crafted lookup expressions to be evaluated against untrusted input. A successful attacker can achieve remote code execution, or potentially information disclosure, on the affected service. Any deployment of Apache Log4j2 that relies on the affected non-default lookup configurations is exposed, which given Log4j2's ubiquity in Java applications and embedded products means a very large installed base. Exploitation is confirmed: the flaw is in CISA KEV (added 2023-05-01) with known ransomware use, and EPSS assigns a 100% probability of exploitation within 30 days. Do: Upgrade Log4j2 to 2.17.0 or later per vendor instructions (or 2.12.3/2.3.1 for the legacy 2.12/2.3 branches), since the 2.16.0 fix was itself incomplete in some non-default configurations. Where upgrading is not immediately possible, remove the JndiLookup class from the Log4j2 jar or disable lookup processing, and audit applications and dependencies that bundle Log4j2 while following the CISA KEV required action to apply vendor updates. | 9.0 | 100% | KEV ransomware |
| massmillions of Java deployments worldwide, with hundreds of thousands of internet-exposed services observed in public scans during the Log4Shell campaign | |
| CVE-2021-45105 | Apache Log4j2 versions 2.0-alpha1 through 2.16.0 (excluding 2.12.3 and 2.3.1) did not protect from uncontrolled recursion from self-referential lookups. Apache Log4j2 versions 2.0-alpha1 through 2.16.0 (excluding 2.12.3 and 2.3.1) did not protect from uncontrolled recursion from self-referential lookups. This allows an attacker with control over Thread Context Map data to cause a denial of service when a crafted string is interpreted. This issue was fixed in Log4j 2.17.0, 2.12.3, and 2.3.1. NVD description · AI analysis pending | 5.9 | 100% |
| — |
Full article541 words · extracted from thehackernews.com · click to collapse
Ravie LakshmananDec 23, 2021
Cybersecurity agencies from Australia, Canada, New Zealand, the U.K., and the U.S. on Wednesday released a joint advisory in response to widespread exploitation of multiple vulnerabilities in Apache's Log4j software library by nefarious adversaries.
"These vulnerabilities, especially Log4Shell, are severe," the intelligence agencies said in the new guidance. "Sophisticated cyber threat actors are actively scanning networks to potentially exploit Log4Shell, CVE-2021-45046, and CVE-2021-45105 in vulnerable systems. These vulnerabilities are likely to be exploited over an extended period."
An attacker can exploit Log4Shell (CVE-2021-44228) by submitting a specially crafted request to a vulnerable system that causes that system to execute arbitrary code. CVE-2021-45046, on the other hand, allows for remote code execution in certain non-default configurations, while CVE-2021-45105 could be leveraged by a remote attacker to cause a denial-of-service (DoS) condition.
Since the vulnerabilities became public knowledge this month, unpatched servers have come under siege from ransomware groups to nation-state hackers, who have used the attack vector as a conduit to gain access to networks to deploy Cobalt Strike beacons, cryptominers, and botnet malware.
The U.S. Federal Bureau of Investigation's (FBI) assessment of the attacks has also raised the possibility that threat actors are incorporating the flaws into "existing cyber criminal schemes that are looking to adopt increasingly sophisticated obfuscation techniques." In light of the severity of the vulnerabilities and likely increased exploitation, organizations are being urged to identify, mitigate, and update affected assets as soon as possible.
To that end, the U.S. Cybersecurity and Infrastructure Security Agency (CISA) has also released a scanner utility to identify systems vulnerable to the Log4Shell vulnerability, mirroring a similar tool released by the CERT Coordination Center (CERT/CC).
However, Israeli cybersecurity firm Rezilion, in an assessment published this week, found that commercial scanning tools were ill-equipped to detect all formats of the Log4j library in an environment due to the fact that the instances are often deeply nested in other code, revealing the "blindspots" in such utilities and the limitations of static scanning.
"The biggest challenge lies in detecting Log4Shell within packaged software in production environments: Java files (such as Log4j) can be nested a few layers deep into other files — which means that a shallow search for the file won't find it," Yotam Perkal, vulnerability research lead at Rezilion, said. "Furthermore, they may be packaged in many different formats which creates a real challenge in digging them inside other Java packages."
The public disclosure of Log4Shell has also led a number of technology suppliers to deploy patches for software that contain the flaw. The latest companies to issue updates are NVIDIA and HPE, joining a long list of vendors that have published security advisories detailing the products that are affected by the vulnerability.
The latest step taken by the governments arrives as the Apache Software Foundation (ASF) on Monday released updates for Apache HTTP Server to address two flaws — CVE-2021-44790 (CVSS score: 9.8) and CVE-2021-44224 (CVSS score: 8.2) — the former of which could be weaponized by a remote attacker to execute arbitrary code and take control of an affected system.
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Text extracted automatically; images, tables and formatting may be missing. Original: https://thehackernews.com/2021/12/cisa-fbi-and-nsa-publish-joint-advisory.html