CVE-2019-9495
Description
A flaw was found in wpa_supplicant. Side channel attacks were recently discovered in the SAE implementations used by both hostapd and wpa_supplicant. EAP-pwd uses a similar design for deriving PWE from the password and while a specific attack against EAP-pwd is not yet known to be tested, there is no reason to believe that the EAP-pwd implementation would be immune against the type of cache attack that was identified for the SAE implementation. Since the EAP-pwd implementation in hostapd (EAP server) and wpa_supplicant (EAP peer) does not support MODP groups, the timing attack described against SAE is not applicable for the EAP-pwd implementation. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability.
Statement
This issue did not affect the versions of wpa_supplicant as shipped with Red Hat Enterprise Linux 5, 6 as they did not include support for EAP-pwd.
This issue did not affect the versions of wpa_supplicant as shipped with Red Hat Enterprise Linux 7 as they are not compiled with EAP-pwd enabled. In particular, the CONFIG_EAP_PWD=y option is not set at compile time.
An attacker must be able to run unprivileged code on the victim's machine to be able to exploit it, lowering the severity of this flaw to Moderate.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 7 | 3.7 | N/A |
| Attack Vector | Local | Network | N/A |
| Attack Complexity | High | High | N/A |
| Privileges Required | Low | None | N/A |
| User Interaction | None | None | N/A |
| Scope | Unchanged | Unchanged | N/A |
| Confidentiality | High | Low | N/A |
| Integrity Impact | High | None | N/A |
| Availability Impact | High | None | N/A |
Vector
Red Hat: CVSS:3.0/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
NVD: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N
Understanding the Weakness (CWE)
Confidentiality,Access Control
Technical Impact: Read Application Data; Bypass Protection Mechanism
An attacker can gain access to sensitive information about the system, including authentication information that may allow an attacker to gain access to the system. Other security-relevant information about the operation or internal state of the product may be revealed to an unauthorized actor, such as whether a particular operation was successful or not.
Confidentiality
Technical Impact: Read Application Data
In some cases, discrepancies can be used by attackers to form a side channel. When cryptographic primitives are vulnerable to side-channel attacks, this could be used to reveal unencrypted plaintext in the worst case.
Acknowledgements
Red Hat would like to thank Eyal Ronen (Tel Aviv University & KU Leuven) and Mathy Vanhoef (NYUAD) for reporting this issue.
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