CVE-2022-20019 in MT6595
Summary
by MITRE • 01/04/2022
In libMtkOmxGsmDec, there is a possible information disclosure due to an incorrect bounds check. This could lead to local information disclosure with no additional execution privileges needed. User interaction is not needed for exploitation. Patch ID: ALPS05917620; Issue ID: ALPS05917620.
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Analysis
by VulDB Data Team • 05/22/2025
The vulnerability identified as CVE-2022-20019 resides within the libMtkOmxGsmDec component of MediaTek's OpenMAX IL implementation, specifically affecting the GSM decoder module. This issue represents a classic bounds checking flaw that allows for unauthorized data access through improper memory boundary validation. The vulnerability manifests in the OMX (Open Media Framework) implementation used in Android devices, where the decoder component fails to properly validate array indices or buffer sizes during GSM frame processing operations.
The technical flaw stems from an incorrect bounds check implementation that permits memory access beyond intended buffer boundaries. When processing GSM encoded audio frames, the decoder does not adequately verify that data access operations remain within allocated memory limits. This oversight creates a condition where adjacent memory regions can be read without proper authorization, potentially exposing sensitive information such as cryptographic keys, system memory contents, or other confidential data structures. The vulnerability operates at the media framework level, making it particularly concerning as it affects core multimedia processing functionality that handles audio and video data streams.
From an operational perspective, this vulnerability enables local information disclosure without requiring any additional privileges or user interaction for exploitation. The attack vector is straightforward since the flaw exists within a legitimate system component that processes media data routinely. Any application or process that utilizes the GSM decoder functionality can trigger the vulnerability, making it potentially exploitable by malicious applications already present on the device. The lack of user interaction requirements significantly increases the attack surface and reduces the barrier to exploitation, as the vulnerability can be triggered automatically during normal media processing operations.
The impact of this information disclosure vulnerability aligns with CWE-129, which describes improper validation of array indices, and is categorized under the broader class of buffer over-read conditions. This weakness allows attackers to read memory contents that should remain protected, potentially exposing sensitive information that could be leveraged for further attacks. The vulnerability's classification as a local information disclosure means that even without remote access capabilities, an attacker with local system access or a compromised application can extract confidential data. Security frameworks such as the ATT&CK matrix would categorize this under privilege escalation and information gathering techniques, as it enables unauthorized data access through legitimate system components.
Mitigation strategies should focus on implementing proper bounds checking mechanisms within the media framework components, particularly in the OMX decoder implementations. The patch referenced in ALPS05917620 addresses the specific bounds check issue by correcting the validation logic to ensure proper array boundary enforcement. System administrators and device manufacturers should prioritize applying the vendor-specific patch to prevent exploitation. Additionally, implementing memory protection mechanisms such as stack canaries, address space layout randomization, and enhanced memory sanitization tools can provide additional defense layers. Regular security audits of media processing components and implementation of strict input validation protocols should be maintained to prevent similar vulnerabilities from emerging in future releases.