not to be confused with software cracking
KRACK ( “ Key Reinstallation Attack “ ) is a play back attack ( a type of exploitable flaw ) on the Wi-Fi Protected Access protocol that secures Wi-Fi connections. It was discovered in 2016 [ 1 ] by the belgian researchers Mathy Vanhoef and Frank Piessens of the University of Leuven. [ 2 ] Vanhoef ‘s research group published details of the attack in October 2017. [ 3 ] By repeatedly resetting the time being transmitted in the third base step of the WPA2 handshake, an attacker can gradually match encrypted packets seen before and learn the full keychain used to encrypt the dealings. The weakness is exhibited in the Wi-Fi standard itself, and not due to errors in the implementation of a sound standard by individual products or implementations. therefore, any right implementation of WPA2 is likely to be vulnerable. [ 4 ] The vulnerability affects all major software platforms, including Microsoft Windows, macOS, io, Android, Linux, OpenBSD and others. [ 3 ]
Reading: KRACK – Wikipedia
The widely used open-source execution wpa_supplicant, utilized by Linux and Android, was specially susceptible as it can be manipulated to install an all-zeros encoding key, effectively nullifying WPA2 protection in a man-in-the-middle attack. [ 5 ] [ 6 ] Version 2.7 fixed this vulnerability. [ 7 ] The security protocol protecting many Wi-Fi devices can basically be bypassed, potentially allowing an attacker to intercept [ 8 ] send and received data .
Details [edit ]
The attack targets the four-way handshake used to establish a time being ( a kind of “ shared secret “ ) in the WPA2 protocol. The standard for WPA2 anticipates occasional Wi-Fi disconnections, and allows reconnection using the same value for the one-third handshake ( for quick reconnection and continuity ). Because the standard does not require a different key to be used in this type of reconnection, which could be needed at any time, a replay attack is possible. An attacker can repeatedly re-send the third handshake of another device ‘s communication to manipulate or reset the WPA2 encoding key. [ 9 ] Each reset causes data to be encrypted using the lapp values, so blocks with the same content can be seen and matched, working backwards to identify parts of the keychain which were used to encrypt that block of data. Repeated resets gradually expose more of the keychain until finally the hale key is known, and the attacker can read the target ‘s entire traffic on that connection. According to US-CERT :
Read more: Ciphertext indistinguishability – Wikipedia
“ US-CERT has become mindful of several key management vulnerabilities in the 4-way handshake of the Wi-Fi Protected Access II ( WPA2 ) security protocol. The impact of exploiting these vulnerabilities includes decoding, packet replay, TCP connection commandeer, HTTP content injection, and others. Note that as protocol-level issues, most or all right implementations of the standard will be affected. The CERT/CC and the report research worker KU Leuven, will be publicly disclosing these vulnerabilities on 16 October 2017. ” [ 10 ]
The paper describing the vulnerability is available on-line, [ 11 ] and was formally presented at the ACM Conference on Computer and Communications Security on 1 November 2017. [ 5 ] US-CERT is tracking this vulnerability, listed as VU # 228519, across multiple platforms. [ 12 ] The adopt CVE identifiers relate to the KRACK vulnerability : CVE – 2017-13077, CVE- 2017-13078, CVE- 2017-13079, CVE- 2017-13080, CVE- 2017-13081, CVE- 2017-13082, CVE- 2017-13084, CVE- 2017-13086, CVE- 2017-13087 and CVE – 2017-13088. [ 5 ] Some WPA2 users may counter the attack by updating Wi-Fi client and access steer device software, if they have devices for which seller patches are available. [ 13 ] however, vendors may delay in offering a spot, or not provide patches at all in the case of many older devices. [ 13 ] [ 1 ]
Patches [edit ]
Patches are available for unlike devices to protect against KRACK, starting at these versions :
Workarounds [edit ]
In order to mitigate risk on vulnerable clients, some WPA2-enabled Wi-Fi access points have shape options that can disable EAPOL-Key [ clarification needed ] human body re-transmission during key installation. Attackers can not cause re-transmissions with a delayed frame transmission, thereby denying them access to the network, provided TDLS is not enabled. [ 24 ] One disadvantage of this method acting is that, with poor connectivity, key reinstallation failure may cause failure of the Wi-Fi connect.
Read more: A Few Thoughts on Cryptographic Engineering
continue vulnerability [edit ]
In October 2018, reports emerged that the KRACK vulnerability was inactive exploitable in cattiness of seller patches, through a assortment of workarounds for the techniques used by vendors to close off the original attack. [ 25 ]