CVE-2025-20740VulnerabilityPublished 4 Nov 2025

CVE-2025-20740: MediaTek MT7902, MT7920, MT7921, MT7922, MT7925, MT7927 · Time-of-check Time-of-use (TOCTOU) Race Condition

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

Not known to be exploited · CVSS 4.7 Medium.

Data as of 25 Oct 2026, 19:02 UTC

CVSS 3.1 base score

4.7Medium

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

EPSS: 0.1% chance of exploitation in 30 days – higher than 0% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

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

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

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: High: A successful attack depends on conditions beyond the attacker's control. That is, a successful attack cannot be accomplished at will, but requires the attacker to invest in some measurable amount of effort in preparation or execution against the vulnerable component before a successful attack can be expected. For example, a successful attack may require an attacker to: gather knowledge about the environment in which the vulnerable target/component exists; prepare the target environment to improve exploit reliability; or inject themselves into the logical network path between the target and the resource requested by the victim in order to read and/or modify network communications (e.g., a man in the middle attack).
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: High: There is total loss of confidentiality, resulting in all resources within the impacted component being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact.
Integrity: None: There is no loss of integrity within the impacted component.
Availability: None: There is no impact to availability within the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 4 Nov 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

1. Apply official patches from MediaTek as soon as they become available, specifically addressing Patch ID WCNCR00435337. 2. For devices where patches are not yet available, restrict local user access to trusted personnel only and enforce strict user privilege management to minimize the risk of exploitation. 3. Implement endpoint detection and response (EDR) solutions to monitor for anomalous behavior related to driver exploitation or memory access patterns. 4. Conduct regular firmware and driver inventory audits to identify devices using affected MediaTek chipsets and NB SDK versions 3.7 or earlier. 5. Employ network segmentation to isolate devices with vulnerable wireless hardware from critical systems. 6. Use application whitelisting and privilege restriction to prevent unauthorized code execution that could leverage this vulnerability. 7. Educate IT staff and users about the risks of local privilege misuse and the importance of applying security updates promptly. 8. Monitor threat intelligence feeds for any emerging exploits targeting this vulnerability to enable rapid incident response. 9. Coordinate with device vendors and suppliers to ensure timely updates and support for affected hardware. 10. Consider temporary mitigation such as disabling affected wireless interfaces in high-risk environments until patches are deployed.

Description

In wlan STA driver, there is a possible out of bounds read due to a race condition. This could lead to local information disclosure with User execution privileges needed. User interaction is not needed for exploitation. Patch ID: WCNCR00435337; Issue ID: MSV-4036.

Impact

For European organizations, the primary impact of CVE-2025-20740 is the potential local disclosure of sensitive information through exploitation of the race condition in MediaTek WLAN drivers. This could lead to leakage of credentials, cryptographic keys, or other confidential data stored in memory, undermining data confidentiality. Since the vulnerability requires local user privileges but no user interaction, it poses a risk in environments where untrusted users have local access or where malware could escalate privileges. This is particularly relevant for enterprises with shared workstations, public access terminals, or IoT deployments using affected chipsets. The vulnerability could facilitate lateral movement or privilege escalation chains in targeted attacks. Additionally, compromised wireless drivers could impact network stability or security posture indirectly. Given the widespread use of MediaTek chipsets in consumer and enterprise devices across Europe, the vulnerability could affect a broad range of sectors including finance, healthcare, manufacturing, and government. The lack of known exploits currently limits immediate risk, but the potential for future exploitation necessitates proactive mitigation. Failure to address this vulnerability could result in regulatory compliance issues under GDPR if sensitive personal data is exposed.

CWE-367Time-of-check Time-of-use (TOCTOU) Race Condition (opens in a new tab)
Base weaknessLikelihood of exploit: Medium
The product checks the state of a resource before using that resource, but the resource's state can change between the check and the use in a way that invalidates the results of the check.
Implementation
The most basic advice for TOCTOU vulnerabilities is to not perform a check before the use. This does not resolve the underlying issue of the execution of a function on a resource whose state and identity cannot be assured, but it does help to limit the false sense of security given by the check.
Implementation
When the file being altered is owned by the current user and group, set the effective gid and uid to that of the current user and group when executing this statement.
Architecture and Design
Limit the interleaving of operations on files from multiple processes.
OWASP Cheat Sheets
Abuse Case (opens in a new tab)
OWASP ASVS 4.0.3
V1.11.3 (opens in a new tab)
V11.1.6 (opens in a new tab)
V1.11.2 (opens in a new tab)
Attack patterns
Leveraging Race Conditions via Symbolic Links (opens in a new tab)
Leveraging Time-of-Check and Time-of-Use (TOCTOU) Race Conditions (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

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

Community reviews

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Exploitation evidence

What to do

Description

AI analysisMachine-generated, updated 4 Nov 2025, 06:52 UTC

WeaknessesCWE-367

Technical details

References

Community reviews

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