MediaTek MT8863 NR16/NR17/NR17R Modem out-of-bounds write

HistoryDiffrelatejsonxmlCTI

CVSS Meta Temp Score CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.	Current Exploit Price (≈) Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.	CTI Interest Score Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
8.5	$0-$5k	0.34

Summaryinfo

A vulnerability has been found in MediaTek MT2737, MT6813, MT6835, MT6835T, MT6878, MT6878M, MT6879, MT6886, MT6895, MT6895TT, MT6896, MT6897, MT6899, MT6980, MT6980D, MT6983, MT6983T, MT6985, MT6985T, MT6989, MT6989T, MT6990, MT6991, MT8673, MT8676, MT8678, MT8795T, MT8798 and MT8863 NR16/NR17/NR17R and classified as critical. The impacted element is an unknown function of the component Modem. This manipulation causes out-of-bounds write. This vulnerability is tracked as CVE-2025-20634. The attack is possible to be carried out remotely. No exploit exists. It is recommended to apply a patch to fix this issue.

Detailsinfo

A vulnerability has been found in MediaTek MT2737, MT6813, MT6835, MT6835T, MT6878, MT6878M, MT6879, MT6886, MT6895, MT6895TT, MT6896, MT6897, MT6899, MT6980, MT6980D, MT6983, MT6983T, MT6985, MT6985T, MT6989, MT6989T, MT6990, MT6991, MT8673, MT8676, MT8678, MT8795T, MT8798 and MT8863 NR16/NR17/NR17R and classified as critical. Affected by this vulnerability is an unknown part of the component Modem. The manipulation with an unknown input leads to a out-of-bounds write vulnerability. The CWE definition for the vulnerability is CWE-787. The product writes data past the end, or before the beginning, of the intended buffer. As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE is:

In Modem, there is a possible out of bounds write due to a missing bounds check. This could lead to remote code execution, if a UE has connected to a rogue base station controlled by the attacker, with no additional execution privileges needed. User interaction is not needed for exploitation. Patch ID: MOLY01289384; Issue ID: MSV-2436.

It is possible to read the advisory at corp.mediatek.com. This vulnerability is known as CVE-2025-20634 since 11/01/2024. The exploitation appears to be easy. The attack can be launched remotely. The exploitation doesn't need any form of authentication. The technical details are unknown and an exploit is not publicly available.

Applying the patch MOLY01289384 is able to eliminate this problem.

Be aware that VulDB is the high quality source for vulnerability data.

Productinfo

Type

Chip Software

Vendor

MediaTek

Name

Version

License

commercial

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 8.6
VulDB Meta Temp Score: 8.5

VulDB Base Score: 7.3
VulDB Temp Score: 7.0
VulDB Vector: 🔍
VulDB Reliability: 🔍

NVD Base Score: 9.8
NVD Vector: 🔍

ADP CISA Base Score: 8.8
ADP CISA Vector: 🔍

CVSSv2info

AV	AC	Au	C	I	A
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Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
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VulDB Base Score: 🔍
VulDB Temp Score: 🔍
VulDB Reliability: 🔍

Exploitinginfo

Class: Out-of-bounds write
CWE: CWE-787 / CWE-119
CAPEC: 🔍
ATT&CK: 🔍

Physical: No
Local: No
Remote: Yes

Availability: 🔍
Status: Not defined

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

0-Day	Unlock	Unlock	Unlock	Unlock
Today	Unlock	Unlock	Unlock	Unlock

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Patch
Status: 🔍

0-Day Time: 🔍

Patch: MOLY01289384

Timelineinfo

11/01/2024 🔍
02/03/2025 +94 days 🔍
02/03/2025 +0 days 🔍
02/17/2026 +379 days 🔍

Sourcesinfo

Advisory: MSV-2436
Status: Confirmed

CVE: CVE-2025-20634 (🔍)
GCVE (CVE): GCVE-0-2025-20634
GCVE (VulDB): GCVE-100-294367

Entryinfo

Created: 02/03/2025 06:49
Updated: 02/17/2026 18:26
Changes: 02/03/2025 06:49 (57), 03/18/2025 15:41 (12), 02/17/2026 18:26 (11)
Complete: 🔍
Cache ID: 216::103