Vulnerabilities in audio decoders of Qualcomm and MediaTek: Check Point

Check Point Research (CPR) identified vulnerabilities in the audio decoders of Qualcomm and MediaTek, the two largest chip manufacturers.
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The vulnerabilities could have led an attacker to remotely get access to media and audio conversations, Check Point Research said. CPR estimates that over two-thirds of the world’s phones were vulnerable at some point. The vulnerable code is based on code shared by Apple 11 years ago.

Vulnerabilities could be used by an attacker for remote code execution attack (RCE) on a mobile device through a malformed audio file.

Impact of an RCE vulnerability can range from malware execution to an attacker gaining control over a user’s multimedia data, including streaming from a compromised machine’s camera.

In addition, an unprivileged Android app could use these vulnerabilities to escalate its privileges and gain access to media data and user conversations.

CPR disclosed findings to Qualcomm and MediaTek, who issued fixes.

Vulnerabilities were found in Apple Lossless Audio Codec (ALAC), also known as Apple Lossless. ALAC is an audio coding format, developed by Apple and first introduced in 2004 for lossless data compression of digital music.

In late 2011 Apple made the codec open source. Since then, the ALAC format has been embedded in many non-Apple audio playback devices and programs, including Android-based smartphones, Linux and Windows media players and converters.

Since then Apple has been updating the proprietary version of the decoder several times, fixing and patching security issues, but the shared code has not been patched since 2011. CPR discovered that Qualcomm and MediaTek ported the vulnerable ALAC code into their audio decoders.

Check Point Research responsibly disclosed the information to MediaTek and Qualcomm and worked closely in collaboration with both vendors to make sure these vulnerabilities were fixed. MediaTek assigned CVE-2021-0674 and CVE-2021-0675 to the ALAC issues.

The vulnerabilities were already fixed and published in the December 2021 MediaTek Security Bulletin. Qualcomm released the patch for CVE-2021-30351 in the December 2021 Qualcomm Security Bulletin. CPR enabled time for users to apply the patches.

Check Point Research is not sharing the technical details of its research findings at this time. Those details will be presented during the CanSecWest conference in May 2022.