CVE-2012-2808 in Android
Summary
by MITRE
The PRNG implementation in the DNS resolver in Bionic in Android before 4.1.1 incorrectly uses time and PID information during the generation of random numbers for query ID values and UDP source ports, which makes it easier for remote attackers to spoof DNS responses by guessing these numbers, a related issue to CVE-2015-0800.
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Analysis
by VulDB Data Team • 04/19/2021
The vulnerability identified as CVE-2012-2808 resides within the pseudorandom number generator implementation of the DNS resolver component in Android's Bionic library. This flaw specifically affects Android versions prior to 4.1.1 and represents a significant security weakness in the operating system's network communication infrastructure. The issue stems from the predictable nature of random number generation used for critical DNS query parameters, creating exploitable patterns that adversaries can leverage to compromise network integrity.
The technical flaw manifests in how the DNS resolver generates random numbers for two critical fields: query ID values and UDP source ports. These values are essential for maintaining the integrity of DNS communications by ensuring that responses can be properly matched to their corresponding queries. The implementation incorrectly relies on time and process identifier information during the random number generation process, which significantly reduces the entropy of the generated values. This approach creates predictable sequences that can be reverse-engineered by attackers with minimal computational resources.
The operational impact of this vulnerability extends beyond simple DNS spoofing capabilities, as it provides attackers with a method to manipulate DNS resolution processes and potentially redirect network traffic. By accurately guessing the query IDs and UDP source ports, malicious actors can craft spoofed DNS responses that appear legitimate to the victim system. This vulnerability directly relates to the broader category of DNS cache poisoning attacks and represents a fundamental weakness in the Android operating system's security architecture. The issue is particularly concerning because it affects the core network resolution functionality that applications and system components depend upon for internet connectivity.
The vulnerability aligns with CWE-330, which addresses the use of insufficiently random values, and demonstrates characteristics consistent with ATT&CK technique T1110.001 for credential access through password guessing and T1071.004 for application layer protocol traffic manipulation. The predictable nature of the random number generation creates a pathway for attackers to perform man-in-the-middle attacks on DNS communications, potentially leading to complete network compromise. This weakness enables adversaries to intercept and modify DNS traffic, redirect users to malicious websites, and potentially gain access to sensitive network resources through compromised DNS resolution.
Mitigation strategies for CVE-2012-2808 require immediate system updates to Android 4.1.1 or later versions where the vulnerability has been addressed through improved random number generation algorithms. Organizations should also implement additional network security measures including DNSSEC deployment, network monitoring for suspicious DNS traffic patterns, and firewall rules that restrict unnecessary DNS traffic. The fix involves strengthening the entropy sources used in random number generation by incorporating more unpredictable system variables and ensuring proper seeding of the pseudorandom number generator with sufficient entropy. Security teams should also conduct thorough network assessments to identify any potential exploitation attempts and implement intrusion detection systems specifically configured to monitor for DNS spoofing activities.