Bug 1946680 (CVE-2021-30004) - CVE-2021-30004 wpa_supplicant: mishandled AlgorithmIdentifier parameters may lead to forging attacks
Summary: CVE-2021-30004 wpa_supplicant: mishandled AlgorithmIdentifier parameters may ...
Keywords:
Status: CLOSED NOTABUG
Alias: CVE-2021-30004
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
medium
medium
Target Milestone: ---
Assignee: Red Hat Product Security
QA Contact:
URL:
Whiteboard:
Depends On: 1947676 1947677
Blocks: 1946681
TreeView+ depends on / blocked
 
Reported: 2021-04-06 16:31 UTC by Guilherme de Almeida Suckevicz
Modified: 2021-04-09 11:35 UTC (History)
8 users (show)

Fixed In Version: wpa_supplicant 2.10
Doc Type: If docs needed, set a value
Doc Text:
A flaw was found in wpa_supplicant, in the way it handled digest algorithm parameters when validating a signature. This flaw could be exploited to perform potential forging attacks. The highest threat from this vulnerability is to data integrity.
Clone Of:
Environment:
Last Closed: 2021-04-09 11:35:09 UTC
Embargoed:


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Description Guilherme de Almeida Suckevicz 2021-04-06 16:31:49 UTC
In wpa_supplicant and hostapd 2.9, forging attacks may occur because AlgorithmIdentifier parameters are mishandled in tls/pkcs1.c and tls/x509v3.c.

Reference and upstream patch:
https://w1.fi/cgit/hostap/commit/?id=a0541334a6394f8237a4393b7372693cd7e96f15

Comment 2 Mauro Matteo Cascella 2021-04-09 09:51:54 UTC
Statement:

This issue only affects the "internal" TLS implementation. The versions of `wpa_supplicant` as shipped with Red Hat Enterprise Linux 6, 7, and 8 are not affected by this flaw, as they use the OpenSSL implementation by default. More specifically, the `CONFIG_TLS=internal` flag is not set at compile time.

Comment 3 Mauro Matteo Cascella 2021-04-09 10:16:30 UTC
In reply to comment #2:
> More specifically, the `CONFIG_TLS=internal` flag is not set at
> compile time.

CONFIG_TLS is not set in the build time configuration file:

# Select TLS implementation
# openssl = OpenSSL (default)
# gnutls = GnuTLS
# internal = Internal TLSv1 implementation (experimental)
# linux = Linux kernel AF_ALG and internal TLSv1 implementation (experimental)
# none = Empty template
#CONFIG_TLS=openssl

This is an excerpt of the Makefile:

ifndef CONFIG_TLS
CONFIG_TLS=openssl
endif
...
ifeq ($(CONFIG_TLS), internal)
...
OBJS += ../src/tls/x509v3.o
OBJS += ../src/tls/pkcs1.o
...

As can be seen, the affected object files are included if CONFIG_TLS=internal, but CONFIG_TLS is set to openssl a few lines above.

Comment 4 Product Security DevOps Team 2021-04-09 11:35:09 UTC
This bug is now closed. Further updates for individual products will be reflected on the CVE page(s):

https://access.redhat.com/security/cve/cve-2021-30004


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