Debian DSA-4430-1 : wpa - security update
Medium Nessus Plugin ID 124038
SynopsisThe remote Debian host is missing a security-related update.
DescriptionMathy 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-2019-9497 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).
SolutionUpgrade the wpa packages.
For the stable distribution (stretch), these problems have been fixed in version 2:2.4-1+deb9u3.