Bug 1058438 (CVE-2017-3226) - VUL-0: CVE-2017-3226: u-boot: Information Exposure Through Timing Discrepancy
Summary: VUL-0: CVE-2017-3226: u-boot: Information Exposure Through Timing Discrepancy
Status: RESOLVED INVALID
Alias: CVE-2017-3226
Product: SUSE Security Incidents
Classification: Novell Products
Component: Incidents (show other bugs)
Version: unspecified
Hardware: Other Other
: P5 - None : Normal
Target Milestone: ---
Assignee: Andreas Färber
QA Contact: Security Team bot
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Reported: 2017-09-13 06:47 UTC by Alexander Bergmann
Modified: 2017-09-13 07:18 UTC (History)
3 users (show)

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Description Alexander Bergmann 2017-09-13 06:47:11 UTC 
CWE-208: Information Exposure Through Timing Discrepancy - CVE-2017-3226

Devices that make use of Das U-Boot's AES-CBC encryption feature using environment encryption (i.e., setting the configuration parameter CONFIG_ENV_AES=y) read environment variables from disk as the encrypted disk image is processed. An attacker with physical access to the device can manipulate the encrypted environment data to include a crafted two-byte sequence which triggers an error in environment variable parsing. This error condition is improperly handled by Das U-Boot, resulting in an immediate process termination with a debugging message.

The immediate failure can be used as an oracle for a Vaudenay-style timing attack on the cryptography, allowing a dedicated attacker to decrypt and potentially modify the contents of the device.

References:
https://www.kb.cert.org/vuls/id/166743
Comment 1 Guillaume GARDET 2017-09-13 06:54:48 UTC 
It is not a real problem since this code is not used inside U-Boot and will be removed in the next releases.
See: https://lists.denx.de/pipermail/u-boot/2017-September/305181.html

No U-Boot configs are using CONFIG_ENV_AES=y. So, I guess we are fine here.
Comment 2 Alexander Bergmann 2017-09-13 07:18:42 UTC 
Neither SLE nor openSUSE is using the AES encryption inside u-boot.

Closing as invalid.