The CVE-2024-27919 vulnerability affects Envoy Proxy, an open-source edge and service proxy widely used in cloud-native applications. This vulnerability allows attackers to exploit the HTTP/2 protocol stack in versions 1.29.0 and 1.29.1 by flooding the system with CONTINUATION frames. The issue arises because Envoy's HTTP/2 codec fails to reset a request after exceeding header map limits, leading to unlimited memory consumption. As a result, this vulnerability can cause denial of service (DoS) through memory exhaustion, impacting the availability of services relying on Envoy.
With a CVSS score of 7.5, classified as high severity, the exploitation of this vulnerability poses a significant risk to organizations that utilize Envoy Proxy. Attackers may leverage this vulnerability to disrupt services, making it critical for organizations to address this issue promptly. Users are encouraged to upgrade to version 1.29.2 or later to mitigate the effects of this vulnerability. If immediate upgrading is not feasible, a temporary workaround includes downgrading to version 1.28.1 or earlier or disabling the HTTP/2 protocol for downstream connections.
Organizations should prioritize patching immediately to protect against potential exploitation. As this vulnerability can lead to severe operational disruptions, it is essential to evaluate the current deployment of Envoy Proxy and take the necessary steps to remediate the identified risks.
The urgency for defenders is underscored by the potential impact on service availability and the ease with which this vulnerability can be exploited. Keeping systems updated and applying security patches is a fundamental practice in maintaining a secure operational environment.
Vulnerability Details
Envoy's HTTP/2 protocol stack is vulnerable to the flood of CONTINUATION frames, as detailed in the official description. The vulnerability affects versions 1.29.0 and 1.29.1, leading to a high severity score of 7.5 on the CVSS scale. Users are advised to upgrade to version 1.29.2 or later to mitigate potential risks. The CWE classification for this vulnerability is CWE-390.
Technical Analysis
The root cause of this vulnerability is the insufficient handling of CONTINUATION frames within Envoy's HTTP/2 codec. When header map limits are exceeded, the codec does not reset the request, allowing attackers to send an unlimited sequence of CONTINUATION frames without the END_HEADERS bit set. This leads to a significant impact on the availability of the service as it consumes memory resources until exhaustion.
The attack vector is network-based, and the complexity of executing such an attack is low, requiring no privileges or user interaction. The impact on confidentiality and integrity is none, but the availability impact is high, indicating that successful exploitation could lead to service outages.
Risk & Impact Analysis
The deployment of Envoy Proxy in an organization's infrastructure increases the risk of a denial of service due to CVE-2024-27919. As services become increasingly dependent on cloud-native architectures, the potential for widespread disruption grows. Organizations should consider the blast radius of this vulnerability, as it could affect multiple services relying on the Envoy Proxy for load balancing and service discovery.
Given the high CVSS score of 7.5 and the potential for exploitation, the urgency for organizations to remediate this vulnerability is classified as high. Security teams should prioritize the application of patches and consider additional monitoring to detect any unusual activity that may indicate an ongoing attack.
Exploitation Status
Signal | Status |
|---|---|
Known Exploit | Yes |
Public PoC | Yes |
Actively Exploited | No |
Ransomware Use | No |
Affected Versions
The affected versions of Envoy Proxy include 1.29.0 and 1.29.1. Users are advised to upgrade to version 1.29.2 or later to address this vulnerability. If upgrade is not possible, downgrading to version 1.28.1 or earlier is recommended.
Mitigation & Remediation
To mitigate this vulnerability, users should upgrade to version 1.29.2 or later of Envoy Proxy. For organizations unable to upgrade immediately, it is recommended to downgrade to version 1.28.1 or earlier or to disable the HTTP/2 protocol for downstream connections. Ongoing monitoring should be conducted to detect any signs of exploitation.
For further guidance on security testing, organizations can consider implementing continuous security testing to validate the effectiveness of their security measures.
Detection Guidance
Organizations should monitor logs for any anomalies related to memory usage and HTTP/2 requests. Detection of high memory consumption events may indicate an ongoing attack attempting to exploit this vulnerability. Additionally, behavioral anomalies in service interactions that deviate from established patterns should be closely investigated.
AppSecure Threat Intelligence Insight
The CVE-2024-27919 vulnerability illustrates the challenges organizations face in maintaining secure cloud-native architectures. As the usage of Envoy Proxy increases, understanding and addressing vulnerabilities becomes critical. This incident underscores the necessity for security teams to adopt robust vulnerability management practices.
For organizations looking to enhance their security posture, insights from recent trends can be beneficial. Engaging in a comprehensive penetration testing methodology can help in identifying potential vulnerabilities before they are exploited.
Furthermore, utilizing a vulnerability management program can assist organizations in developing a proactive approach to security, ensuring timely remediation of vulnerabilities.
Lastly, keeping abreast of new advisories and patches will help organizations remain vigilant against emerging threats. Regularly updating and reviewing security protocols is essential in the fight against cyber threats.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
.webp)