Bug 1699168 (CVE-2019-9498) - CVE-2019-9498 wpa_supplicant: EAP-pwd server missing commit validation for scalar/element
Summary: CVE-2019-9498 wpa_supplicant: EAP-pwd server missing commit validation for sc...
Keywords:
Status: CLOSED NOTABUG
Alias: CVE-2019-9498
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
high
high
Target Milestone: ---
Assignee: Red Hat Product Security
QA Contact:
URL:
Whiteboard:
Depends On:
Blocks: 1687612
TreeView+ depends on / blocked
 
Reported: 2019-04-12 00:26 UTC by Laura Pardo
Modified: 2019-09-29 15:11 UTC (History)
18 users (show)

Fixed In Version:
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Last Closed: 2019-06-10 10:54:00 UTC


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Description Laura Pardo 2019-04-12 00:26:40 UTC
An attack using invalid scalar/element values is possible against the EAP-pwd server since hostapd and wpa_supplicant did not validate these values in the received EAP-pwd-Commit messages. When processing an EAP-pwd Commit frame, the peer's scalar and element (elliptic curve point) were not validated. This allowed an adversary to bypass authentication, and impersonate any user if the crypto implementation did not verify the validity of the EC point.

The vulnerability is only exploitable if OpenSSL version 1.0.2 or lower is used, or if LibreSSL or wolfssl is used. Newer versions of OpenSSL (and also BoringSSL) implicitly validate the elliptic curve point in EC_POINT_set_affine_coordinates_GFp(), preventing the attack.


References:
https://w1.fi/security/2019-4/eap-pwd-missing-commit-validation.txt
https://wpa3.mathyvanhoef.com/

Upstream Patch:
https://w1.fi/cgit/hostap/commit/?id=16d4f1069118aa19bfce013493e1ac5783f92f1d
https://w1.fi/cgit/hostap/commit/?id=70ff850e89fbc8bc7da515321b4d15b5eef70581

Comment 1 Riccardo Schirone 2019-04-12 09:48:35 UTC
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.

Comment 4 Laura Pardo 2019-04-12 20:34:07 UTC
Acknowledgments:

Name: Mathy Vanhoef (NYUAD), Eyal Ronen (Tel Aviv University & KU Leuven)


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