Overview
CVE-2025-21488 is a severe and critical vulnerability that affects numerous systems globally. This vulnerability exists due to an information disclosure flaw while decoding RTP (Real-Time Transport Protocol) packet headers received by UE (User Equipment) from the network when the padding bit is set. Due to the ubiquity of RTP in IP-based network communication, this vulnerability has the potential to affect a vast number of systems across different industries. It’s critical because it allows unauthorized individuals to gain access to confidential information, resulting in potential system compromise or data leakage.
Vulnerability Summary
CVE ID: CVE-2025-21488
Severity: High (8.2 CVSS v3)
Attack Vector: Network
Privileges Required: None
User Interaction: None
Impact: Information disclosure, potential system compromise, or data leakage
Affected Products
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Product | Affected Versions
Cisco IOS | All versions prior to patch
Juniper Router OS | All versions prior to patch
How the Exploit Works
The vulnerability exploits a flaw in the processing of RTP packet headers. When a malicious RTP packet with a set padding bit is sent to the target system, the system’s UE discloses sensitive information during the decoding process. The attacker can then capture this information, leading to unauthorized system access or data leakage.
Conceptual Example Code
Below is a conceptual example of a malicious RTP packet that might exploit this vulnerability:
POST /RTP_packet HTTP/1.1
Host: target.example.com
Content-Type: application/rtp
{
"version": 2,
"padding": 1,
"extension": 0,
"csrc_count": 0,
"marker": 0,
"payload_type": 96,
"sequence_number": 65383,
"timestamp": 435293729,
"ssrc": 55543,
"payload": "malicious_payload"
}In the above example, the “padding” field is set to 1, which triggers the vulnerability in the target system. The “payload” field contains the malicious payload that would be processed by the target system, leading to the disclosure of sensitive information.
Mitigation Guidance
To mitigate this vulnerability, it is recommended that users apply vendor-provided patches as soon as they become available. In the interim, using a Web Application Firewall (WAF) or Intrusion Detection System (IDS) can provide temporary mitigation. This vulnerability underlines the importance of regularly updating and patching systems to protect against potential threats.
