The U.S. Cybersecurity and Infrastructure Security Agency (CISA) has recently made a significant update to its Known Exploited Vulnerabilities (KEV) catalog by adding a critical security flaw in Apache Flink. This flaw, identified as CVE-2020-17519, has been found to pose serious risks due to improper access control, which could potentially lead to unauthorized access to sensitive information.
CISA’s decision to include vulnerabilities like the one in Apache Flink in its catalog stems from the recognition that these vulnerabilities are often exploited by malicious cyber actors, putting federal enterprises at risk. The catalog serves as a vital tool for identifying and addressing actively exploited vulnerabilities in the cybersecurity landscape.
The CVE-2020-17519 vulnerability in Apache Flink, a popular open-source framework for stream-processing and batch-processing, arises from improper access control within versions 1.11.0, 1.11.1, and 1.11.2. This flaw allows remote attackers to access specific files in the local JobManager filesystem through carefully crafted directory traversal requests, potentially leading to unauthorized access to sensitive data.
While specifics about the ongoing exploitation of the Apache Flink vulnerability remain unclear, it has been noted that this flaw has existed for at least four years and has been acknowledged by a project maintainer. The vulnerability was initially brought to light by “0rich1” from Ant Security FG Lab, with exploit code for the vulnerability publicly accessible. Additionally, researchers from Palo Alto Networks identified the vulnerability as one of the most commonly exploited during the Winter 2020 period, emphasizing the urgency of addressing such vulnerabilities promptly.
In response to the CVE-2020-17519 vulnerability, the Apache Software Foundation released patches in January 2021 with Flink versions 1.11.3 and 1.12.0, prompting users to upgrade to secure their systems. CISA has mandated federal agencies to apply these necessary patches by June 13, 2024, as part of the Binding Operational Directive (BOD) aimed at safeguarding federal agency networks against active threats.
While the directive specifically targets Federal Civilian Executive Branch (FCEB) agencies, CISA has encouraged all organizations to mitigate their exposure to cyber threats by following vendor instructions for applying necessary patches or discontinuing the use of affected products if mitigation options are unavailable.
The discovery of vulnerabilities in widely used open-source projects like Apache Flink and Apache Commons Text underscores the importance of implementing timely updates and patches to protect against potential cyber threats. These incidents serve as a reminder of the ever-evolving nature of cybersecurity risks and the critical role of proactive mitigation strategies.
In conclusion, the addition of the Apache Flink vulnerability to CISA’s Known Exploited Vulnerabilities catalog highlights the ongoing need for vigilance and prompt action in addressing cybersecurity vulnerabilities to safeguard sensitive data and organizational assets from malicious exploitation.