CVE-2026-41499

#include <stdio.h> #include <string.h> #include <stdlib.h> // PoC simulation of the vulnerable logic in Wazuh parse_uname_string() void trigger_vulnerability(char* input_string) { char* buffer = (char*)malloc(256); if (!buffer) return; printf("[+] Allocating buffer at: %p\n", buffer); // Vulnerable logic pattern found in remoted_op.c size_t len = strlen(input_string); printf("[+] Input string length: %zu\n", len); // If input_string is "", len is 0. // len - 1 becomes SIZE_MAX (unsigned integer underflow). // This writes to buffer[-1], corrupting heap metadata. buffer[len - 1] = 'X'; printf("[+] Write operation completed.\n"); free(buffer); // Likely to crash here due to heap corruption } int main() { printf("PoC for CVE-2026-41499: Wazuh Heap Overflow\n"); printf("Triggering the vulnerability with an empty string...\n"); // Sending an empty string triggers the underflow trigger_vulnerability(""); return 0; }

{"cve": {"id": "CVE-2026-41499", "sourceIdentifier": "[email protected]", "published": "2026-04-29T19:16:23.780", "lastModified": "2026-05-01T13:01:08.190", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "Wazuh is a free and open source platform used for threat prevention, detection, and response. From version 4.0.0 to before version 4.14.4, multiple heap-based out-of-bounds WRITE vulnerabilities exist in parse_uname_string() (remoted_op.c). This function processes OS identification data from agents and contains a dangerous code pattern that appears in 4 locations within the same function: writing to strlen(ptr) - 1 without checking for empty strings. When the string is empty, strlen() returns 0, and 0 - 1 wraps to SIZE_MAX due to unsigned integer underflow. Due to pointer arithmetic wrapping, SIZE_MAX effectively becomes -1, causing a write exactly 1 byte before the allocated buffer. This corrupts heap metadata (e.g., the chunk size field in glibc malloc), leading to heap corruption. This issue has been patched in version 4.14.4."}], "metrics": {"cvssMetricV31": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H", "baseScore": 6.5, "baseSeverity": "MEDIUM", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "LOW", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "availabilityImpact": "HIGH"}, "exploitabilityScore": 2.8, "impactScore": 3.6}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-124"}, {"lang": "en", "value": "CWE-191"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:wazuh:wazuh:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.0.0", "versionEndExcluding": "4.14.4", "matchCriteriaId": "8147D947-167A-4F70-A689-81B33A161A83"}]}]}], "references": [{"url": "https://github.com/wazuh/wazuh/releases/tag/v4.14.4", "source": "[email protected]", "tags": ["Release Notes"]}, {"url": "https://github.com/wazuh/wazuh/security/advisories/GHSA-qvqj-p8mm-r7h3", "source": "[email protected]", "tags": ["Vendor Advisory"]}, {"url": "https://github.com/wazuh/wazuh/security/advisories/GHSA-qvqj-p8mm-r7h3", "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "tags": ["Vendor Advisory"]}]}}