PT-2024-33310 · Arm · Mbed Os

Diff-Fusion

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Published

2024-11-20

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Updated

2024-11-25

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CVE-2024-48981

CVSS v3.1

7.5

High

VectorAV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
Name of the Vulnerable Software and Affected Versions MBed OS version 6.16.0
Description An issue was discovered in the processing of HCI packets. The software dynamically determines the length of the packet header by looking up the identifying first byte and matching it against a table of possible lengths. The initial parsing function, hciTrSerialRxIncoming, does not drop packets with invalid identifiers but also does not set a safe default for the length of unknown packets' headers, leading to a buffer overflow. This can be leveraged into an arbitrary write by an attacker. It is possible to overwrite the pointer to a not-yet-allocated buffer that is supposed to receive the contents of the packet body. One can then overwrite the state variable used by the function to determine which state of packet parsing is currently occurring. Because the buffer is allocated when the last byte of the header has been copied, the combination of having a bad header length variable that will never match the counter variable and being able to overwrite the state variable with the resulting buffer overflow can be used to advance the function to the next step while skipping the buffer allocation and resulting pointer write. The next 16 bytes from the packet body are then written wherever the corrupted data pointer is pointing.
Recommendations As a temporary workaround, consider disabling the hciTrSerialRxIncoming function until a patch is available. Restrict access to the vulnerable module to minimize the risk of exploitation. Avoid using the affected API endpoint until the issue is resolved. At the moment, there is no information about a newer version that contains a fix for this vulnerability.

Buffer Overflow

Weakness Enumeration

CWE-120

Related Identifiers

CVE-2024-48981

Affected Products

Mbed Os