Debian Security Advisory

DLA-2827-1 bluez -- LTS security update

Date Reported:
27 Nov 2021
Affected Packages:
Security database references:
In the Debian bugtracking system: Bug 1000262.
In Mitre's CVE dictionary: CVE-2019-8921, CVE-2019-8922, CVE-2021-41229.
More information:

Several vulnerabilities were discovered in BlueZ, the Linux Bluetooth protocol stack. An attacker could cause a denial-of-service (DoS) or leak information.

  • CVE-2019-8921

    SDP infoleak; the vulnerability lies in the handling of a SVC_ATTR_REQ by the SDP implementation of BlueZ. By crafting a malicious CSTATE, it is possible to trick the server into returning more bytes than the buffer actually holds, resulting in leaking arbitrary heap data.

  • CVE-2019-8922

    SDP Heap Overflow; this vulnerability lies in the SDP protocol handling of attribute requests as well. By requesting a huge number of attributes at the same time, an attacker can overflow the static buffer provided to hold the response.

  • CVE-2021-41229

    sdp_cstate_alloc_buf allocates memory which will always be hung in the singly linked list of cstates and will not be freed. This will cause a memory leak over time. The data can be a very large object, which can be caused by an attacker continuously sending sdp packets and this may cause the service of the target device to crash.

For Debian 9 stretch, these problems have been fixed in version 5.43-2+deb9u5.

We recommend that you upgrade your bluez packages.

For the detailed security status of bluez please refer to its security tracker page at:

Further information about Debian LTS security advisories, how to apply these updates to your system and frequently asked questions can be found at: