Bug 1960009 (CVE-2020-26557)
| Summary: | CVE-2020-26557 kernel: predictable Authvalue in Bluetooth Mesh Provisioning Leads to MITM | ||
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| Product: | [Other] Security Response | Reporter: | Guilherme de Almeida Suckevicz <gsuckevi> |
| Component: | vulnerability | Assignee: | Nobody <nobody> |
| Status: | NEW --- | QA Contact: | |
| Severity: | medium | Docs Contact: | |
| Priority: | medium | ||
| Version: | unspecified | CC: | acaringi, adscvr, airlied, alciregi, bhu, blc, bmasney, bnocera, chwhite, crwood, darcari, dvlasenk, dwmw2, dzickus, hdegoede, hkrzesin, hwkernel-mgr, jarodwilson, jeremy, jforbes, jlelli, jonathan, josef, jshortt, jstancek, jwboyer, kcarcia, kernel-maint, kernel-mgr, lgoncalv, linville, masami256, mchehab, mlangsdo, nmurray, ptalbert, qzhao, rkeshri, rvrbovsk, spacewar, steved, walters, wcosta, williams, wmealing |
| Target Milestone: | --- | Keywords: | Security |
| Target Release: | --- | ||
| Hardware: | All | ||
| OS: | Linux | ||
| Whiteboard: | |||
| Fixed In Version: | Doc Type: | If docs needed, set a value | |
| Doc Text: |
A flaw was found in the Linux kernel’s Bluetooth Mesh Profile implementation. The Mesh Provisioning procedure has a vulnerability that allows an attacker observing or taking part in the provisioning to brute force the AuthValue if it has a fixed value or is selected predictably or with low entropy. If successful, an attacker can identify the AuthValue and authenticate to both the Provisioner and provisioned devices, allowing a Man-in-the-Middle (MITM) attack on a future provisioning attempt with the same AuthValue. The highest threat from this vulnerability is to confidentiality, integrity, as well as system availability.
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Story Points: | --- |
| Clone Of: | Environment: | ||
| Last Closed: | Type: | --- | |
| Regression: | --- | Mount Type: | --- |
| Documentation: | --- | CRM: | |
| Verified Versions: | Category: | --- | |
| oVirt Team: | --- | RHEL 7.3 requirements from Atomic Host: | |
| Cloudforms Team: | --- | Target Upstream Version: | |
| Embargoed: | |||
| Bug Depends On: | 1969609, 1969610, 1969618 | ||
| Bug Blocks: | 1969593 | ||
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Description
Guilherme de Almeida Suckevicz
2021-05-12 19:11:46 UTC
Mitigation: It is recommended for devices to use AuthValues containing the maximum entropy permitted (128-bits) and randomly select a new AuthValue using a secure random number generator with each new provisioning attempt. A large entropy helps ensure that a brute-force of the AuthValue, even a static AuthValue, cannot normally be completed in a reasonable time. Created bluez tracking bugs for this issue: Affects: fedora-all [bug 1969618] |