CVE-2020-11833

Source: security@oppo.com

MEDIUM
5.5
Published: December 31, 2020 at 06:15 PM
Modified: November 21, 2024 at 04:58 AM

Vulnerability Description

In /SM8250_Q_Master/android/vendor/oppo_charger/oppo/charger_ic/oppo_mp2650.c, the function mp2650_data_log_write in mp2650_data_log_write does not check the parameter len which causes a vulnerability.

CVSS Metrics

Base Score
5.5
Severity
MEDIUM
Vector String
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Weaknesses (CWE)

Source: nvd@nist.gov

AI Security Analysis

01 // Technical Summary

A critical vulnerability exists in the OPPO charger IC driver (mp2650.c) due to a missing bounds check, allowing for arbitrary data writes. This flaw can lead to denial-of-service (DoS) conditions or, potentially, remote code execution (RCE) on affected devices. Successful exploitation could compromise device integrity and user data.

02 // Vulnerability Mechanism

Step 1: Triggering the Vulnerability: An attacker crafts a malicious input, likely through a communication channel with the charger IC driver. This input includes a crafted len value.

Step 2: Function Call: The attacker's input triggers a call to the vulnerable mp2650_data_log_write function.

Step 3: Missing Bounds Check: The mp2650_data_log_write function receives the crafted len value, but it does not validate it against the size of the allocated buffer.

Step 4: Buffer Overflow: The function proceeds to write data to the buffer, using the attacker-controlled len value. Since len exceeds the buffer size, a buffer overflow occurs.

Step 5: Exploitation (DoS or RCE): The overflow overwrites adjacent memory regions. This can corrupt critical data structures, leading to a crash (DoS). Alternatively, if the attacker can control the overwritten data, they may be able to overwrite the return address or other control flow data, leading to arbitrary code execution (RCE).

03 // Deep Technical Analysis

The vulnerability lies within the mp2650_data_log_write function in oppo_mp2650.c. The function fails to validate the len parameter, which specifies the size of the data to be written. This lack of bounds checking allows an attacker to provide a len value exceeding the allocated buffer size. This results in a buffer overflow, where data is written beyond the intended memory boundaries. Depending on the memory layout and the attacker's control over the data, this could lead to a crash (DoS) or, with careful crafting of the overflow, the execution of arbitrary code (RCE). The root cause is a missing input validation step, a common software development error.

04 // Exploitation Status

Likely **Discovery Only**. While the vulnerability is well-defined, the specific exploitation path (RCE) would require significant reverse engineering and device-specific knowledge. No public PoCs are readily available, but the nature of the vulnerability suggests it could be exploited by skilled attackers.

05 // Threat Intelligence

Due to the nature of the affected component (charger IC driver), it's less likely to be targeted by widespread malware campaigns. However, sophisticated APTs with a focus on mobile device exploitation could potentially leverage this vulnerability. No specific APT groups are directly linked to this CVE. Not listed in CISA KEV.

06 // Detection & Hunting

  • Analyze system logs for unexpected errors or crashes related to the charger IC driver or related hardware components.

  • Monitor for unusual network traffic patterns associated with device charging or communication with the charger IC.

  • Examine firmware images for the presence of the vulnerable mp2650_data_log_write function and its associated code.

  • Implement kernel-level monitoring to detect memory corruption events or suspicious write operations to the charger IC driver's memory space.

  • Use static analysis tools to identify potential buffer overflows in the mp2650_data_log_write function.

07 // Remediation & Hardening

  • Apply the vendor's security patch or firmware update that addresses the vulnerability. This is the primary and most effective remediation step.

  • Implement input validation within the mp2650_data_log_write function to ensure the len parameter is within acceptable bounds. This should include checking against the allocated buffer size.

  • Employ memory protection mechanisms, such as address space layout randomization (ASLR) and data execution prevention (DEP/NX), to mitigate the impact of potential buffer overflows.

  • Regularly update the device's operating system and firmware to incorporate the latest security patches.

  • Conduct thorough code reviews of the charger IC driver and related components to identify and eliminate other potential vulnerabilities.

08 // Affected Products

OPPO devices using the /SM8250_Q_Master/android/vendor/oppo_charger/oppo/charger_ic/oppo_mp2650.c driver.Specific device models and Android versions are unknown, but any device using the vulnerable driver is potentially affected.
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