A possible arbitrary file read and SSRF vulnerability has been identified in Apache Kafka Client. Apache Kafka Clients accept configuration data for setting the SASL/OAUTHBEARER connection with the brokers, including "sasl.oauthbearer.token.endpoint.url" and "sasl.oauthbearer.jwks.endpoint.url". Apache Kafka allows clients to read an arbitrary file and return the content in the error log, or send requests to an unintended location. In applications where Apache Kafka Clients configurations can be specified by an untrusted party, attackers may use the "sasl.oauthbearer.token.endpoint.url" and "sasl.oauthbearer.jwks.endpoint.url" configuration to read arbitrary contents of the disk and environment variables or make requests to an unintended location.
In particular, this flaw may be used in Apache Kafka Connect to escalate from REST API access to filesystem/environment/URL access, which may be undesirable in certain environments, including SaaS products. Since Apache Kafka 3.9.1/4.0.0, a system property ("-Dorg.apache.kafka.sasl.oauthbearer.allowed.urls") has been added to set the allowed URLs in SASL JAAS configuration. In version 3.9.1, it accepts all URLs by default for backward compatibility. However, in version 4.0.0 and newer, the default value is an empty list and users have to set the allowed URLs explicitly.
Risk to organizations includes unauthorized access to sensitive files and information leakage. Attackers may leverage this vulnerability to execute SSRF attacks, potentially leading to further exploitation within the environment. Organizations should prioritize patching immediately.
The CVSS score for this vulnerability is 7.5, indicating a high level of severity. The vulnerability has a high exploitability rating, and as such, it is essential for organizations utilizing Apache Kafka to assess their configurations and implement necessary mitigations.
Organizations should address this vulnerability in their priority patch cycle to mitigate risks effectively.
Vulnerability Details
CVE-2025-27817 describes an arbitrary file read and SSRF vulnerability present in Apache Kafka Client. The affected versions include all Apache Kafka releases prior to version 3.9.1. The vulnerability allows untrusted configurations to exploit the aforementioned SASL/OAUTHBEARER connection settings.
The CVSS score of 7.5 categorizes this vulnerability as high severity, indicating a critical need for organizations to address it promptly. The vulnerability is classified under CWE-918.
Technical Analysis
The root cause of this vulnerability lies in the improper handling of configuration data, allowing attackers to specify arbitrary URLs for reading files or making requests. The attack vector is network-based, with low complexity and no privileges required for exploitation. User interaction is not necessary, making this vulnerability particularly dangerous.
The confidentiality impact is high, as unauthorized access to sensitive data is possible. However, there is no integrity or availability impact associated with this vulnerability.
Risk & Impact Analysis
Organizations that deploy Apache Kafka are at significant risk of unauthorized access to sensitive information. The potential for data exfiltration and subsequent exploitation is a critical concern. The urgency for remediation is heightened by the high exploitability rating and the potential for direct attacks on production environments.
Organizations should prioritize this vulnerability in their patch management processes, considering the CVSS score and the potential blast radius of this flaw. Immediate attention is warranted to prevent further exploitation.
Exploitation Status
Signal | Status |
|---|---|
Known Exploit | Yes |
Public PoC | Yes |
Actively Exploited | No |
Ransomware Use | No |
Affected Versions
Apache Kafka versions 3.1.0 through 3.9.0 are affected by this vulnerability. All versions prior to the vendor patch are susceptible to exploitation.
Mitigation & Remediation
Organizations should upgrade to Apache Kafka version 4.0.0 or later to mitigate this vulnerability. If an immediate upgrade is not possible, it is crucial to set the allowed URLs explicitly in the SASL JAAS configuration. Configuration hardening should be performed to limit untrusted configurations.
Additionally, organizations should implement network controls to restrict access to sensitive components of the infrastructure. Continuous monitoring is recommended to detect any anomalous behavior associated with this vulnerability.
For further information on penetration testing, organizations can refer to penetration testing services to validate their security posture.
Detection Guidance
Monitoring logs for unusual access patterns or unexpected file reads can provide indicators of compromise. Behavioral anomalies in application responses should also be scrutinized. Setting up network signatures to detect unauthorized requests may help in identifying exploitation attempts.
AppSecure Threat Intelligence Insight
The long-term significance of this vulnerability highlights the need for robust input validation and configuration management within application development. This CVE represents a trend where improper handling of external configurations leads to severe security implications.
Security teams should focus on implementing strict validation mechanisms for configurations that can be influenced by untrusted sources. The strategic takeaway is to enforce security best practices in application design and deployment.
For more insights on vulnerability management, organizations can explore vulnerability management programs and best practices.
Additionally, organizations should consider reviewing their penetration testing methodologies to ensure they encompass all aspects of potential vulnerabilities.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
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