CVE-2017-2721 in Berlin
Summary
by MITRE
Some Huawei smart phones with software Berlin-L21C10B130,Berlin-L21C185B133,Berlin-L21HNC10B131,Berlin-L21HNC185B140,Berlin-L21HNC432B151,Berlin-L22C636B160,Berlin-L22HNC636B130,Berlin-L22HNC675B150CUSTC675D001,Berlin-L23C605B131,Berlin-L24HNC567B110,FRD-L02C432B120,FRD-L02C635B130,FRD-L02C675B170CUSTC675D001,FRD-L04C567B162,FRD-L04C605B131,FRD-L09C10B130,FRD-L09C185B130,FRD-L09C432B131,FRD-L09C636B130,FRD-L14C567B162,FRD-L19C10B130,FRD-L19C432B131,FRD-L19C636B130 have a factory Reset Protection (FRP) bypass security vulnerability. When re-configuring the mobile phone using the factory reset protection (FRP) function, an attacker can login the configuration flow by Swype Keyboard and can perform some operations to update the Google account. As a result, the FRP function is bypassed.
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Analysis
by VulDB Data Team • 01/11/2023
The vulnerability identified as CVE-2017-2721 represents a critical security flaw in various Huawei smartphone models that utilize specific software versions including Berlin-L21C10B130, Berlin-L21C185B133, and numerous others listed in the CVE description. This vulnerability specifically targets the Factory Reset Protection (FRP) mechanism that is designed to prevent unauthorized access to devices following a factory reset operation. The FRP feature serves as a crucial security control that typically requires users to authenticate with their Google account credentials before they can fully utilize a device after a reset, thereby preventing theft-related misuse of lost or stolen smartphones. The flaw manifests when attackers exploit a weakness in the device's configuration flow process, allowing them to circumvent the normal authentication sequence through the Swype Keyboard input method.
The technical exploitation of this vulnerability occurs during the device reconfiguration phase when users attempt to restore their smartphones to factory settings. Attackers can manipulate the configuration workflow by utilizing the Swype Keyboard functionality to navigate through the setup process and gain access to Google account update operations without proper authentication. This bypass mechanism allows unauthorized individuals to effectively disable the FRP protection entirely, rendering the security controls ineffective. The vulnerability stems from insufficient validation controls within the device's setup process, particularly during the account configuration phase where the system should enforce strict authentication requirements. The weakness creates a pathway for malicious actors to perform operations that should require legitimate user credentials, effectively undermining the fundamental security principle of device access control.
The operational impact of this vulnerability extends beyond simple security bypass to potentially enable widespread device theft and unauthorized access scenarios. When FRP protection is circumvented, stolen devices become immediately usable by thieves without the need for the original owner's account credentials, significantly diminishing the deterrent effect that FRP typically provides against smartphone theft. This vulnerability particularly affects users who rely on their smartphones for sensitive data storage and communications, as the bypass allows attackers to access personal information, emails, messages, and other device contents without authorization. The implications are further compounded by the fact that this vulnerability affects multiple Huawei smartphone models across different software versions, indicating a systemic flaw rather than an isolated incident. The attack vector is particularly concerning as it can be executed through seemingly legitimate configuration workflows that users regularly encounter during device setup or recovery processes.
Security mitigations for CVE-2017-2721 should focus on implementing proper authentication controls during device reconfiguration processes and strengthening the validation mechanisms that govern account setup operations. Organizations and users should ensure that all affected Huawei devices receive appropriate software updates from Huawei to address this vulnerability. The recommended approach includes implementing multi-factor authentication requirements for all account configuration processes, particularly during factory reset scenarios, and ensuring that keyboard input methods cannot bypass the established authentication flow. Additionally, network administrators should consider implementing device management policies that enforce regular security updates and monitor for unauthorized device configurations. This vulnerability aligns with CWE-287 which addresses improper authentication issues, and corresponds to ATT&CK technique T1072 which covers software deployment and configuration, highlighting the importance of maintaining secure configuration processes and proper access controls throughout the device lifecycle.