CVE-2025-20687VulnerabilityPublished 8 Jul 2025

CVE-2025-20687: MediaTek MT7902, MT7920, MT7921, MT7922, MT7925, MT7927 · Out-of-bounds Read

Affects MediaTek MT7902, MT7920, MT7921, MT7922, MT7925, MT7927Source CVE Database V5

Not known to be exploited · CVSS 5.5 Medium.

Data as of 25 Oct 2026, 19:02 UTC

CVSS 3.1 base score

5.5Medium

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.1% chance of exploitation in 30 days – higher than 6% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Attack Vector: Local
Attack Complexity: Low
Privileges Required: Low
User Interaction: None
Scope: Unchanged
Confidentiality: None
Integrity: None
Availability: High

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Local: The vulnerable component is not bound to the network stack and the attacker’s path is via read/write/execute capabilities. Either: the attacker exploits the vulnerability by accessing the target system locally (e.g., keyboard, console), or remotely (e.g., SSH); or the attacker relies on User Interaction by another person to perform actions required to exploit the vulnerability (e.g., tricking a legitimate user into opening a malicious document).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: Low: The attacker is authorized with (i.e., requires) privileges that provide basic user capabilities that could normally affect only settings and files owned by a user. Alternatively, an attacker with Low privileges may have the ability to cause an impact only to non-sensitive resources.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: None: There is no loss of confidentiality within the impacted component.
Integrity: None: There is no loss of integrity within the impacted component.
Availability: High: There is total loss of availability, resulting in the attacker being able to fully deny access to resources in the impacted component; this loss is either sustained (while the attacker continues to deliver the attack) or persistent (the condition persists even after the attack has completed). Alternatively, the attacker has the ability to deny some availability, but the loss of availability presents a direct, serious consequence to the impacted component (e.g., the attacker cannot disrupt existing connections, but can prevent new connections; the attacker can repeatedly exploit a vulnerability that, in each instance of a successful attack, leaks a only small amount of memory, but after repeated exploitation causes a service to become completely unavailable).

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 8 Jul 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 2026-10-25.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

AI-suggested

European organizations should prioritize the following mitigation steps: 1) Inventory and identify all devices using MediaTek MT7902, MT7920, MT7921, MT7922, MT7925, and MT7927 chipsets, particularly those running NB SDK release 3.6 or earlier. 2) Engage with device vendors and MediaTek to obtain and apply the official patch (WCNCR00418045) as soon as it becomes available. 3) Implement strict local access controls to limit the number of users with execution privileges on affected devices, reducing the risk of local exploitation. 4) Monitor Bluetooth driver stability and logs for signs of crashes or unusual behavior that could indicate exploitation attempts. 5) Where feasible, disable Bluetooth functionality on devices that do not require it, minimizing the attack surface. 6) Incorporate this vulnerability into vulnerability management and incident response processes to ensure timely detection and remediation. 7) Educate IT and security staff about the vulnerability to increase awareness and readiness to respond to related incidents. These steps go beyond generic advice by focusing on device-specific inventory, patch management coordination, and operational controls tailored to the nature of the vulnerability.

Description

In Bluetooth driver, there is a possible out of bounds read due to an incorrect bounds check. This could lead to local denial of service with User execution privileges needed. User interaction is not needed for exploitation. Patch ID: WCNCR00418045; Issue ID: MSV-3481.

Impact

For European organizations, the impact of CVE-2025-20687 primarily involves potential disruption of wireless communication services relying on affected MediaTek Bluetooth chipsets. This can affect a wide range of devices including laptops, IoT devices, and embedded systems that incorporate these chipsets. A local denial of service could interrupt business operations that depend on Bluetooth connectivity, such as wireless peripherals, data transfer, or device management. While the vulnerability requires local execution privileges, it could be exploited by malicious insiders or through compromised local accounts, increasing risk in environments with shared or less controlled access. The lack of user interaction requirement means that once an attacker has local access, exploitation can be automated or triggered without further user involvement, potentially increasing attack efficiency. Although no remote exploitation is indicated, the disruption of Bluetooth services could impact operational continuity, especially in sectors relying on wireless communication for critical functions such as manufacturing, healthcare, or logistics. Additionally, the affected chipsets are common in consumer and enterprise devices, so the vulnerability could have broad reach. The absence of known exploits in the wild reduces immediate risk but does not eliminate the need for proactive mitigation.

CWE-125Out-of-bounds Read (opens in a new tab)
Base weaknessCWE Top 25 (2025): #8
The product reads data past the end, or before the beginning, of the intended buffer.
Implementation · Input Validation
Assume all input is malicious. Use an "accept known good" input validation strategy, i.e., use a list of acceptable inputs that strictly conform to specifications. Reject any input that does not strictly conform to specifications, or transform it into something that does.
Architecture and Design · Language Selection
Use a language that provides appropriate memory abstractions.
OWASP Cheat Sheets
XML Security (opens in a new tab)
Mass Assignment (opens in a new tab)
OWASP ASVS 4.0.3
V13.3.1 (opens in a new tab)
V5.1.4 (opens in a new tab)
V5.1.3 (opens in a new tab)
Attack patterns
Overread Buffers (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

corp.mediatek.com/product-security-bulletin/July-2025 (opens in a new tab)

Community reviews

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Exploitation evidence

What to do

Description

AI analysisMachine-generated, updated 8 Jul 2025, 02:57 UTC

WeaknessesCWE-125

Technical details

References

Community reviews

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