1. INFORMATION
--------------
[+] CVE                : CVE-2022-48334
[+] Title              : Buffer Overflow in Widevine Trustlet 
(drm_verify_keys @ 0x7370)
[+] Vendor             : Google
[+] Device             : Nexus 6
[+] Affected component : Widevine
[+] Publication date   : March 2023
[+] Credits            : CyberIntel Team



2. AFFECTED VERSIONS
--------------------
5.0.0 (LRX21O), 5.0.1 (LRX22C), 5.1.0 (LMY47D), 5.1.0 (LMY47E), 5.1.0 
(LMY47I), 5.1.0 (LMY47M), 5.1.1 (LMY47Z), 5.1.1 (LMY48I), 5.1.1 
(LMY48M), 5.1.1 (LMY48T), 5.1.1 (LMY48W), 5.1.1 (LMY48X), 5.1.1 
(LMY48Y), 5.1.1 (LVY48C), 5.1.1 (LVY48E), 5.1.1 (LVY48F), 5.1.1 
(LVY48H), 5.1.1 (LVY48I), 5.1.1 (LYZ28E), 5.1.1 (LYZ28J), 5.1.1 
(LYZ28K), 5.1.1 (LYZ28M), 5.1.1 (LYZ28N)



3. DETAILS
----------
Qualcomm Secure Execution Environment is one of the most widespread 
commercial TEE solutions in the smartphone space, used by many different 
devices such as Xiaomi, Motorola and several devices of the Google Nexus 
and Pixel series. Widevine is a Digital Rights Management (DRM) 
technology developed by Google to protect copyrighted content and to 
enable secure distribution and consumption of video and audio content. 
The technology involves encryption, licensing, and key management to 
ensure that content can only be decrypted and played back on authorized 
devices. An attacker with high privileges in Normal World can exploit 
the vulnerability to compromise the Trusted Application running in the 
Secure World, eventually executing arbitrary code and reading and/or 
modifying information of critical files, compromising the 
confidentiality and integrity of the system. On the other hand, the 
attacker is able to crash the Trusted Application, potentially resulting 
in a denial of service.

The bug is present in Widevine’s drm_verify_keys() command. This command 
closely resembles drm_save_keys(), which has been featured in other blog 
entries (refer to CVE-2022-48331 and CVE-2022-48332).

For more details and full proof of concept visit 
https://cyberintel.es/cve/CVE-2022-48334_Buffer_Overflow_in_Widevine_drm_verify_keys_0x7370/


--
Cyber Intel Team.
Zero Lab - https://cyberintel.es/