CVE-2015-7263 in Facebook Proxygen
Summary
by MITRE
The SPDY/2 codec in Facebook Proxygen before 2015-11-09 allows remote attackers to conduct hijacking attacks and bypass ACL checks via a crafted host value.
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Analysis
by VulDB Data Team • 08/27/2020
The vulnerability identified as CVE-2015-7263 resides within the SPDY/2 codec implementation of Facebook Proxygen, a high-performance HTTP/2 and SPDY library developed by Facebook. This flaw represents a critical security weakness that enables remote attackers to manipulate connection handling and access control mechanisms within systems utilizing this library. The vulnerability specifically targets the processing of host headers in SPDY/2 protocol implementations, creating opportunities for sophisticated attack vectors that can compromise network security and data integrity.
The technical exploitation of this vulnerability occurs through manipulation of the host value field in SPDY/2 protocol frames. Attackers can craft malicious host headers that exploit implementation gaps in how Proxygen processes these values, allowing them to hijack existing connections or establish unauthorized communication paths. The flaw stems from insufficient validation and sanitization of host header information, particularly when transitioning between different protocol versions or handling connection multiplexing. This creates a scenario where an attacker can manipulate the host resolution process and potentially redirect traffic or bypass established access control lists that should prevent unauthorized access to resources.
The operational impact of CVE-2015-7263 extends beyond simple protocol manipulation to encompass broader security compromise possibilities. Network administrators and security professionals must consider that this vulnerability can enable man-in-the-middle attacks, connection hijacking, and unauthorized access to protected resources. The implications are particularly severe in environments where Proxygen is used as a core component of web infrastructure, as it can allow attackers to bypass existing network security controls and potentially access sensitive data or systems that should remain protected by established access control mechanisms.
The vulnerability aligns with CWE-284, which addresses improper access control issues, and demonstrates how protocol implementation flaws can create security bypass opportunities. From an ATT&CK framework perspective, this vulnerability maps to techniques involving protocol manipulation and connection hijacking, specifically targeting the T1071.002 sub-technique for application layer protocol manipulation. The attack surface is particularly concerning as it affects the fundamental connection handling capabilities of the Proxygen library, making it a prime target for attackers seeking to establish persistent access or conduct data exfiltration operations.
Organizations utilizing Facebook Proxygen should implement immediate mitigations including updating to the patched version released on November 9, 2015, which addressed the host header validation issues. Network segmentation and additional monitoring should be implemented to detect anomalous host header patterns that might indicate exploitation attempts. Security teams should also review existing access control policies and implement additional validation layers to prevent similar vulnerabilities from being exploited in other components of their infrastructure. The remediation process should include comprehensive testing of the updated library in production environments to ensure that the fix does not introduce compatibility issues while effectively addressing the security gap that allowed the hijacking and ACL bypass capabilities.