We have identified a new buffer overflow vulnerability in Samsung’s baseband implementation (mainly used in Exynos chipsets). The vulnerability can be exploited to achieve arbitrary code execution in the baseband runtime. The vulnerability we are disclosing in this advisory affected a wide range of Samsung devices, including phones on the newest Exynos chipsets. The November 2023 issue of the Samsung Semiconductor Security Bulletin contains this vulnerability as CVE-2023-41111. Vulnerability Details Background: Data Block Format and Re-assembly in RLC In GPRS, an LLC layer PDU can be up to 1560 bytes long, but the maximum size for an RLC data block is 22/32/38/52 for the GPRS coding schemes CS-1/2/3/4, respectively.

We have identified several new heap buffer overflow vulnerabilities in Samsung’s baseband implementation (mainly used in Exynos chipsets): three different heap buffer overflows in the same function, to be precise. The most critical of these vulnerabilities can be exploited to achieve arbitrary code execution in the baseband runtime. The vulnerabilities we are disclosing in this advisory affected a wide range of Samsung devices, including phones on the newest Exynos chipsets. The vulnerability report covering all three that we reported together was assigned CVE-2023-41112, which was published in the 2023 November issue of Samsung Semiconductor Security Bulletin. Vulnerability Details Background: RLC Data Block Formats in GPRS vs E-GPRS In GPRS, an LLC layer PDU can be up to 1560 bytes long, but the maximum size for an RLC data block is between 22 and 52 bytes for GPRS, depending on the Coding Scheme used (22/32/38/52 for the GPRS coding schemes CS-1/2/3/4, respectively).

We have identified a new stack buffer overflow vulnerability in Mediatek’s Linux Kernel driver implementation of cellular-to-application processor communication interface (CCCI). The vulnerability can be exploited by a malicious (compromised) baseband runtime to achieve arbitrary code execution in the Linux Kernel. The vulnerability we are disclosing in this advisory affected a wide range of Mediatek devices, including phones on the newest chipsets (Dimensity 700, 1000, etc). The July 2022 issue of the Mediatek Security Bulletin contains this vulnerability as CVE-2022-21766. Vulnerability Details There is a kernel stack buffer overflow vulnerability in the implementation of the modem-kernel communication interface. The stack overflow can be used to overwrite the return address of a kernel function, with attacker controlled data.

We have identified a new heap buffer overflow vulnerability in Mediatek’s baseband implementation. The vulnerability can be exploited to achieve arbitrary code execution in the baseband runtime. The vulnerability we are disclosing in this advisory affected a wide range of Mediatek devices, including phones on the newest chipsets (Dimensity 700, 1000, etc). The July 2022 issue of the Mediatek Security Bulletin contains this vulnerability as CVE-2022-21744. Vulnerability Details The GPRS Packet Neighbour Cell Data (PNCD) message is an optional message sent by the network on the PACCH to provide system information required for initial access in a neighbouring cell. In the case of the MediaTek baseband firmware, this message is processed in the FDD_rmpc_mac_rmpc_pncd_ind_hdlr function.

We have identified a new out-of-bound write vulnerability in Mediatek’s Linux Kernel driver implementation of cellular-to-application processor communication interface (CCCI). The vulnerability can be exploited by a malicious (compromised) baseband runtime to achieve arbitrary code execution in the Linux Kernel. The vulnerability we are disclosing in this advisory affected a wide range of Mediatek devices, including phones on the newest chipsets (Dimensity 700, 1000, etc). The July 2022 issue of the Mediatek Security Bulletin contains this vulnerability as CVE-2022-21765. Vulnerability Details There is a vmalloc out-of-bound write vulnerability in the kernel implementation of the modem-kernel communication interface. The out-of-bound write can be used to write controlled data, with controlled size, at a controlled location within the kernel’s vmalloc memory region.

We have identified a new out-of-bound read vulnerability in Mediatek’s Linux Kernel driver implementation of cellular-to-application processor communication interface (CCCI). The vulnerability can be exploited by a malicious (compromised) baseband runtime to leak information from the kernel runtime and break the kernel’s entropy-based mitigations such as KASLR and stack smashing protection. The vulnerability we are disclosing in this advisory affected a wide range of Mediatek devices, including phones on the newest chipsets (Dimensity 700, 1000, etc). The July 2022 issue of the Mediatek Security Bulletin contains this vulnerability as CVE-2022-21769. Vulnerability Details There is a vmalloc out-of-bound read vulnerability in the kernel implementation of the modem-kernel communication interface.

We have identified a new heap buffer overflow vulnerability in Samsung’s baseband implementation (mainly used in Exynos chipsets). The vulnerability can be exploited to achieve arbitrary code execution in the baseband runtime. The vulnerability we are disclosing in this advisory affected a wide range of Samsung devices, including phones on the newest Exynos chipsets. The June 2023 issue of the Samsung Mobile Security Bulletin contains this vulnerability as CVE-2023-21517. Vulnerability Details Layer 3 LTE NAS messages are composed of various Information Elements and the Exynos modem implementation defines dedicated parser functions for each IE type. The vulnerability is within the parser function of the Traffic Flow Template IE (3GPP TS 24.

Summary There is a vulnerability in the Huawei Kirin SoC’s DDR Controller (DMSS) Access Permission system which allows the baseband to bypass the Baseband’s MPU memory protections and circumvent RO and NX protections. The vulnerability was fixed in February 2022. Vulnerability Details CVE-2021-22430 is a vulnerability in the Huawei Kirin SoC’s basebands which allowed to circumvent MPU restrictions. The vulnerability in CVE-2021-22430 was that MPU configuration was restored from a writable table for sleep cycles and therefore overwriting the cached entries resulted in new settings taking effect. This worked because the implementation normally only wrote the table once (not every time the core went to sleep) but restored the MPU configuration from it every time it was woken up.

Summary There is a vulnerability in the Huawei Kirin SoC’s DDR Controller (DMSS) Access Permission system which allows the Linux kernel to bypass memory access restrictions and directly compromise multiple privileged subsystems of the SoC. As demonstrated by CVE-2021-3710, CVE-2021-39991, CVE-2021-37115, and CVE-2021-39986, read and write of critical system memory, including secure memory regions, is possible via those subsystems. Therefore, this vulnerability combined with one of CVE-2021-3710, CVE-2021-39991, CVE-2021-37115, or CVE-2021-39986 results in a fully realized chain of elevation of privileges from a kernel-level write primitive to total control of the secure world (TEE). The vulnerability was fixed in February 2022.

Summary In this advisory we are disclosing a heap overflow vulnerability in the MediaTek baseband. The vulnerability can be exploited to gain arbitrary code execution in the context of the baseband runtime. The vulnerability was fixed in 2020 in some models, and received a CVE and more widely deployed fix in 2021. Vulnerability Details When processing the CSN.1 decoding of the “E-UTRAN Individual Priority Parameters” element, the function rr_decode_eutran_individual_priority_para_description implements a two-depth nested repetition (Repeated Individual E-UTRAN Priority Parameters Description struct and its child element EARFCN). The outer loop is iterated by checking on the single bit representing the ongoing repetition, and while that equals “1”, a new Repeated Individual E-UTRAN Priority Parameters Description struct is processed.