데비안 보안 권고

DSA-4430-1 wpa -- 보안 업데이트

보고일:
2019년 04월 10일
영향 받는 패키지:
wpa
위험성:
보안 데이터베이스 참조:
데비안 버그 추적 시스템: 버그 926801.
Mitre의 CVE 사전: CVE-2019-9495, CVE-2019-9497, CVE-2019-9498, CVE-2019-9499.
추가 정보:

Mathy Vanhoef (NYUAD) and Eyal Ronen (Tel Aviv University & KU Leuven) found multiple vulnerabilities in the WPA implementation found in wpa_supplication (station) and hostapd (access point). These vulnerability are also collectively known as Dragonblood.

  • CVE-2019-9495

    Cache-based side-channel attack against the EAP-pwd implementation: an attacker able to run unprivileged code on the target machine (including for example javascript code in a browser on a smartphone) during the handshake could deduce enough information to discover the password in a dictionary attack.

  • CVE-2019-9497

    Reflection attack against EAP-pwd server implementation: a lack of validation of received scalar and elements value in the EAP-pwd-Commit messages could result in attacks that would be able to complete EAP-pwd authentication exchange without the attacker having to know the password. This does not result in the attacker being able to derive the session key, complete the following key exchange and access the network.

  • CVE-2019-9498

    EAP-pwd server missing commit validation for scalar/element: hostapd doesn't validate values received in the EAP-pwd-Commit message, so an attacker could use a specially crafted commit message to manipulate the exchange in order for hostapd to derive a session key from a limited set of possible values. This could result in an attacker being able to complete authentication and gain access to the network.

  • CVE-2019-9499

    EAP-pwd peer missing commit validation for scalar/element: wpa_supplicant doesn't validate values received in the EAP-pwd-Commit message, so an attacker could use a specially crafted commit message to manipulate the exchange in order for wpa_supplicant to derive a session key from a limited set of possible values. This could result in an attacker being able to complete authentication and operate as a rogue AP.

Note that the Dragonblood moniker also applies to CVE-2019-9494 and CVE-2014-9496 which are vulnerabilities in the SAE protocol in WPA3. SAE is not enabled in Debian stretch builds of wpa, which is thus not vulnerable by default.

Due to the complexity of the backporting process, the fix for these vulnerabilities are partial. Users are advised to use strong passwords to prevent dictionary attacks or use a 2.7-based version from stretch-backports (version above 2:2.7+git20190128+0c1e29f-4).

안정 배포(stretch)에서 이 문제를 버전 2:2.4-1+deb9u3에서 고쳤습니다.

wpa 패키지를 업그레이드 하는 게 좋습니다.

wpa의 자세한 보안 상태는 보안 추적 페이지 참조: https://security-tracker.debian.org/tracker/wpa