#VU48203 Double Free in BlueZ - CVE-2020-27153

Vulnerability identifier: #VU48203

Vulnerability risk: Medium

CVSSv4.0: 6.6 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2020-27153

CWE-ID: CWE-415

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
BlueZ
Universal components / Libraries / Libraries used by multiple products

Vendor: BlueZ Project

Description

The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

The vulnerability exists due to a boundary error in the gatttool disconnect_cb() routine from shared/att.c. A remote attacker can cause a denial of service or code execution, during service discovery, due to a redundant disconnect MGMT event.

Mitigation
Install update from vendor's website.

Vulnerable software versions

BlueZ: 5.0 - 5.54

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External links
https://bugzilla.redhat.com/show_bug.cgi?id=1884817
https://github.com/bluez/bluez/commit/1cd644db8c23a2f530ddb93cebed7dacc5f5721a
https://github.com/bluez/bluez/commit/5a180f2ec9edfacafd95e5fed20d36fe8e077f07
https://lists.debian.org/debian-lts-announce/2020/10/msg00022.html
https://security.gentoo.org/glsa/202011-01

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Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.