CVE-2012-0333 in Small Business IP phone
Summary
by MITRE
Cisco Small Business IP phones with SPA 500 series firmware 7.4.9 and earlier do not require authentication for Push XML requests, which allows remote attackers to make telephone calls via an XML document, aka Bug ID CSCts08768.
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Analysis
by VulDB Data Team • 01/26/2018
The vulnerability identified as CVE-2012-0333 affects Cisco Small Business IP phones in the SPA 500 series running firmware versions 7.4.9 and earlier. This security flaw represents a critical authentication bypass issue that fundamentally compromises the integrity of the phone's communication system. The vulnerability specifically targets the Push XML functionality, which is designed to enable remote configuration and control of IP phones through XML-based commands. The absence of proper authentication mechanisms for these Push XML requests creates an exploitable condition that allows unauthorized remote access to the device's telephony capabilities.
The technical implementation of this vulnerability stems from the improper handling of XML requests within the phone's firmware architecture. When an attacker sends a specially crafted XML document to the affected phone, the device processes the request without verifying the sender's identity or authorization status. This design flaw falls under the category of inadequate authentication controls and represents a direct violation of security best practices for networked communication devices. The vulnerability is particularly dangerous because it enables attackers to execute arbitrary telephony commands through simple XML payloads, potentially allowing them to make unauthorized calls, access voicemail systems, or modify phone configurations remotely. This issue is classified as a weakness in the authentication mechanism according to CWE-287, which specifically addresses improper handling of authentication tokens or credentials.
The operational impact of this vulnerability extends beyond simple unauthorized calling capabilities and represents a significant threat to enterprise communication security. Remote attackers can exploit this vulnerability to conduct various malicious activities including making premium-rate calls that generate unauthorized charges, accessing sensitive communication channels, or using the phones as entry points for further network infiltration. The vulnerability's remote exploitability means that attackers do not need physical access to the devices or network proximity to compromise them, making it particularly dangerous for distributed enterprise environments. This weakness creates an attack surface that aligns with ATT&CK technique T1190, which involves exploiting vulnerabilities in remote services to gain unauthorized access to systems.
Organizations using affected Cisco SPA 500 series phones face substantial risk from this vulnerability, particularly in environments where telephony systems are integrated with sensitive business communications or financial transaction processes. The lack of authentication for Push XML requests creates a persistent threat vector that can be exploited repeatedly without detection, potentially leading to significant financial losses through unauthorized calling charges or more serious security breaches. The vulnerability's severity is compounded by the fact that many small business environments may not have robust network monitoring or intrusion detection systems in place to detect unauthorized XML requests. Security practitioners should consider this vulnerability as part of a broader assessment of telephony system security, particularly in environments where IP phones are connected to corporate networks or critical infrastructure. The recommended mitigation strategy involves immediate firmware updates to versions that properly implement authentication for Push XML requests, along with network segmentation and monitoring of XML traffic to prevent exploitation attempts.