CVE-2017-2913 in Circle with Disney
Summary
by MITRE
An exploitable vulnerability exists in the filtering functionality of Circle with Disney. SSL certificates for specific domain names can cause the Bluecoat library to accept a different certificate than intended. An attacker can host an HTTPS server with this certificate to trigger this vulnerability.
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Analysis
by VulDB Data Team • 01/06/2023
The vulnerability identified as CVE-2017-2913 represents a critical certificate validation flaw within the Circle with Disney network filtering system that operates through the Bluecoat library. This issue stems from improper SSL certificate handling during domain name validation processes, creating a pathway for man-in-the-middle attacks that can compromise network security. The flaw specifically affects how the system validates certificate chains when processing requests for certain domain names, allowing malicious actors to exploit the certificate matching logic and potentially intercept or manipulate encrypted communications.
This vulnerability operates through a certificate confusion mechanism where the Bluecoat library's certificate validation routine fails to properly verify that the certificate presented matches the expected domain name. The technical implementation appears to rely on partial certificate matching or insufficient validation checks that can be bypassed when an attacker controls an HTTPS server with a malicious certificate. The flaw essentially allows an attacker to present a certificate that passes the library's validation checks even though it does not correspond to the intended domain, creating a trust relationship that should not exist.
The operational impact of this vulnerability extends beyond simple certificate validation failures and represents a significant threat to network security integrity. An attacker who successfully exploits this vulnerability can establish transparent man-in-the-middle positions within the Circle with Disney network, potentially intercepting sensitive data, modifying communications, or redirecting traffic to malicious endpoints. This capability undermines the fundamental security assumptions of SSL/TLS encryption and can affect all network traffic passing through the vulnerable filtering system, particularly impacting users of the Circle with Disney service who rely on secure communications.
The vulnerability aligns with CWE-295, which addresses improper certificate validation, and demonstrates characteristics consistent with attack patterns described in the MITRE ATT&CK framework under the 'Initial Access' and 'Credential Access' domains. This flaw can be exploited to establish persistent network footholds, potentially enabling further lateral movement within the network infrastructure. Organizations using Circle with Disney services should consider this vulnerability as a potential vector for advanced persistent threats and should implement immediate mitigations to protect against exploitation.
Recommended mitigations include immediate deployment of certificate validation updates from Circle with Disney or Bluecoat, implementation of additional certificate pinning mechanisms, and network monitoring to detect suspicious certificate validation patterns. Security teams should also consider implementing certificate transparency monitoring and regular security assessments of SSL/TLS configurations to prevent similar vulnerabilities from persisting. The remediation process should include thorough testing of certificate validation logic and verification that all domain name matching operations properly validate certificate chain integrity to prevent the exploitation pattern described in CVE-2017-2913.