CVE-2023-5055: 
NixOS vulnerability analysis and mitigation

CVE-2023-5055 is a stack-based buffer overflow vulnerability discovered in the Zephyr Real-Time Operating System (RTOS), specifically in the function leecredreconf_req. The vulnerability was disclosed on November 21, 2023, and affects Zephyr versions up to and including 3.4.0 (Zephyr Advisory).

The vulnerability occurs when buf->len is larger than sizeof(chans) / sizeof(scid) multiplied by sizeof(scid), causing chancount to exceed L2CAPECREDCHANMAXPERREQ (which is set to 5). This can result in an Out-Of-Bounds write on line 1385 of the l2cap.c file. Additionally, there are potential security implications with writes to chan.tx, where mtu and msp values are derived from the request. The vulnerability has been assigned a CVSS v3.1 base score of 8.3 (HIGH) with vector: AV:A/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:H (NVD).

The vulnerability can lead to stack-based buffer overflow, potentially resulting in privilege escalation or denial of service. The CVSS scoring indicates high impacts on both integrity and availability of the system, with a lower impact on confidentiality (Zephyr Advisory).

As of the disclosure, no official patches have been released. The issue is being addressed in the main branch (v3.5 development cycle) through pull request #62381 (Zephyr Advisory).