Auth bypass in Elementary Switchboard Bluetooth Plug
CVE-2021-21367
Switchboard Bluetooth Plug for elementary OS from version 2.3.0 and before version version 2.3.5 has an incorrect authorization vulnerability. When the Bluetooth plug is running (in discoverable mode), Bluetooth service requests and pairing requests are automatically accepted, allowing physically proximate attackers to pair with a device running an affected version of switchboard-plug-bluetooth without the active consent of the user. By default, elementary OS doesn't expose any services via Bluetooth that allow information to be extracted by paired Bluetooth devices. However, if such services (i.e. contact list sharing software) have been installed, it's possible that attackers have been able to extract data from such services without authorization. If no such services have been installed, attackers are only able to pair with a device running an affected version without authorization and then play audio out of the device or possibly present a HID device (keyboard, mouse, etc...) to control the device. As such, users should check the list of trusted/paired devices and remove any that are not 100% confirmed to be genuine. This is fixed in version 2.3.5. To reduce the likelihood of this vulnerability on an unpatched version, only open the Bluetooth plug for short intervals when absolutely necessary and preferably not in crowded public areas. To mitigate the risk entirely with unpatched versions, do not open the Bluetooth plug within switchboard at all, and use a different method for pairing devices if necessary (e.g. `bluetoothctl` CLI).
Vulnerability class: Broken Access Control
Published · last modified .
CVSS v3 metric
CVSS v3 base score 6.1 (Medium). Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:L/I:N/A:L.
EPSS exploit prediction
EPSS: 0.005 (41.6th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 42nd percentile — 41.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.005 · newest: 0.005 · change: 0.000
Affected products
- Elementary Switchboard Bluetooth Plug
- Elementary Switchboard-Plug-Bluetooth — versions >= 2.3.0, < 2.3.5
- Fedoraproject Fedora — versions 32, 33
Weakness classification (CWE)
References
- github.com/elementary/switchboard-plug-bluetooth/security/advisories/GHSA-5p3g-… (Patch, Third Party Advisory)
- github.com/elementary/switchboard-plug-bluetooth/releases/tag/2.3.5 (Third Party Advisory, Release Notes)
- github.com/elementary/switchboard-plug-bluetooth/commit/86500e645a907538abafe52… (Patch, Third Party Advisory)
- lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/… (vendor-advisory)
- lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/… (vendor-advisory)
- lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/… (vendor-advisory)
Frequently asked questions
- What is CVE-2021-21367?
- CVE-2021-21367 is a medium-severity vulnerability in Elementary Switchboard Bluetooth Plug, classified under Incorrect Authorization. CVSS score: 6.1/10. Published 2021-03-12.
- How severe is CVE-2021-21367?
- Medium severity. CVSS v3 base score is 6.1 out of 10.