{"id":"CVE-2026-129121","kind":"vulnerability","aliases":["CVE-2026-129121"],"related":[],"title":"C-Kermit: malicious FTP server can overwrite files and run code","description":"C-Kermit 8.0.200 before 11.1.515 contains a path traversal vulnerability in doftpget() in ckcftp.c that allows malicious FTP servers to write files outside the intended directory. Attackers can return absolute paths, tilde names, or dot-dot components in NLST or MLSD listings during MGET /RECURSIVE to overwrite files like .bashrc, leading to code execution.","summary":"C-Kermit's recursive FTP get in doftpget() trusts file names from an FTP server's NLST or MLSD listing. A malicious server can return absolute paths, tilde names or dot-dot components so that files outside the download directory, such as .bashrc, are overwritten, which can lead to code execution.","severity":"medium","cvss":6.9,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["c-kermit","ftp","linux","other","unix"],"not_affected_if":["no-ftp-client-use","trusted-ftp-servers-only"],"how_to_check":"- Check the installed version with `kermit` (look for the version banner) and compare it against the range `8.0.200` to before `11.1.515`.\n- Look for scripts or jobs that run `MGET /RECURSIVE` against FTP servers you do not control.","fix":"- C-Kermit: move to `11.1.515` or later","status":"open","published_at":"2026-11-13T17:17:29+00:00","first_seen_at":"2026-11-13T17:48:00+00:00","triaged_at":"2026-11-13T17:48:59+00:00","updated_at":"2026-11-13T17:48:59+00:00","category":"other","confidence":0.7,"triage":{"at":"2026-11-13T17:48:59Z","model":"claude-haiku-5-5","output":{"fix":"- C-Kermit: move to `11.1.515` or later","reach":"network","title":"C-Kermit: malicious FTP server can overwrite files and run code","impact":"high","summary":"C-Kermit's recursive FTP get in doftpget() trusts file names from an FTP server's NLST or MLSD listing. A malicious server can return absolute paths, tilde names or dot-dot components so that files outside the download directory, such as .bashrc, are overwritten, which can lead to code execution.","audience":"developers","category":"other","nicknames":[],"who_cares":["c-kermit","ftp","linux","unix"],"confidence":0.7,"fix_status":"available","needs_auth":"unknown","worst_case":"Attacker overwrites shell startup files and runs code as the user","analyst_note":"Confirm how the FTP client is reached (who controls the server, whether the MGET /RECURSIVE path needs user action) and whether the vendor advisory gives a detection command, using the linked Vendor advisory and Patch pages.","how_to_check":"- Check the installed version with `kermit` (look for the version banner) and compare it against the range `8.0.200` to before `11.1.515`.\n- Look for scripts or jobs that run `MGET /RECURSIVE` against FTP servers you do not control.","plain_action":"","product_name":"","needs_analyst":true,"not_affected_if":["no-ftp-client-use","trusted-ftp-servers-only"],"who_is_affected":"Teams that use C-Kermit's FTP client (MGET with /RECURSIVE) to download from FTP servers, especially servers they do not fully control. Systems that only use C-Kermit for serial or dial-up work, or never fetch files over FTP, are not exposed through this flaw. The sources do not say whether the flaw is reachable with default settings.","user_interaction":"unknown","product_ecosystem":"","needs_special_setup":"unknown","severity_if_unknown":"unknown"},"cost_usd":0.000796,"input_tokens":4669,"output_tokens":658,"severity_before":"medium"},"analyst_status":null,"analyst_note":null,"search":"'-129121':15A,18A '-2026':14A,17A '/recursive':125C '11.1.515':84C '8.0.200':82C 'absolut':52B,109C 'allow':95C 'attack':106C 'bashrc':70B,130C 'c':2A,20B,27B,80C 'c-kermit':1A,19B,26B,79C 'ckcftp.c':93C 'code':12A,77B,133C 'compon':60B,117C 'contain':85C 'cve':13A,16A 'directori':67B,105C 'doftpget':34B,91C 'dot':58B,59B,115C,116C 'dot-dot':57B,114C 'download':66B 'execut':78B,134C 'file':9A,36B,63B,101C,128C 'ftp':5A,22B,31B,40B,97C 'get':32B 'intend':104C 'kermit':3A,21B,28B,81C 'lead':75B,131C 'like':129C 'linux':23B 'list':46B,122C 'malici':4A,48B,96C 'mget':124C 'mlsd':45B,121C 'name':37B,55B,112C 'nlst':43B,119C 'outsid':64B,102C 'overwrit':8A,127C 'overwritten':72B 'path':53B,87C,110C 'recurs':30B 'return':51B,108C 'run':11A 'server':6A,41B,49B,98C 'tild':54B,111C 'travers':88C 'trust':35B 'unix':25B 'vulner':89C 'write':100C","nicknames":[],"mitigations":[],"who_affected":"Teams that use C-Kermit's FTP client (MGET with /RECURSIVE) to download from FTP servers, especially servers they do not fully control. Systems that only use C-Kermit for serial or dial-up work, or never fetch files over FTP, are not exposed through this flaw. The sources do not say whether the flaw is reachable with default settings.","tier":"C","verified":{},"analyst_revisit_at":null,"fix_status":"available","audience":"developers","plain_action":null,"pkeys":[],"ptokens":[],"labels":["ckermit","ftp","linux","medium","other","unix"],"campaign_type":null,"search_a":"'-129121':15A,18A '-2026':14A,17A 'c':2A 'c-kermit':1A 'code':12A 'cve':13A,16A 'file':9A 'ftp':5A 'kermit':3A 'malici':4A 'overwrit':8A 'run':11A 'server':6A","search_b":"'absolut':52B 'bashrc':70B 'c':20B,27B 'c-kermit':19B,26B 'code':77B 'compon':60B 'directori':67B 'doftpget':34B 'dot':58B,59B 'dot-dot':57B 'download':66B 'execut':78B 'file':36B,63B 'ftp':22B,31B,40B 'get':32B 'kermit':21B,28B 'lead':75B 'linux':23B 'list':46B 'malici':48B 'mlsd':45B 'name':37B,55B 'nlst':43B 'outsid':64B 'overwritten':72B 'path':53B 'recurs':30B 'return':51B 'server':41B,49B 'tild':54B 'trust':35B 'unix':25B","search_c":"'/recursive':125C '11.1.515':84C '8.0.200':82C 'absolut':109C 'allow':95C 'attack':106C 'bashrc':130C 'c':80C 'c-kermit':79C 'ckcftp.c':93C 'code':133C 'compon':117C 'contain':85C 'directori':105C 'doftpget':91C 'dot':115C,116C 'dot-dot':114C 'execut':134C 'file':101C,128C 'ftp':97C 'intend':104C 'kermit':81C 'lead':131C 'like':129C 'list':122C 'malici':96C 'mget':124C 'mlsd':121C 'name':112C 'nlst':119C 'outsid':102C 'overwrit':127C 'path':87C,110C 'return':108C 'server':98C 'tild':111C 'travers':88C 'vulner':89C 'write':100C","cause_entry":null,"cause_path":null,"disclosures_checked_at":null,"first_public_at":"2026-10-31T01:21:24+00:00","kev":null,"cvss_vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","cvss_by":"disclosure@vulncheck.com","poc_count":0,"sources":[{"source":"nvd","external_id":"CVE-2026-129121","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-129121","severity":null,"published_at":"2026-11-13T17:17:29+00:00","modified_at":"2026-11-13T17:17:29+00:00","first_seen_at":"2026-11-13T17:48:00+00:00","fetched_at":"2026-11-13T17:48:00+00:00","note":null}],"documents":[{"id":148095,"url":"https://github.com/OpenKermit/ckermit/commit/9b1809b2ce2bcec08b7285deb1b7f0bcbef6a052","title":"Patch: github.com","kind":"other","source":"nvd","publisher":"vendor","text":null,"published_at":null,"relation":"fix","confidence":null,"note":"Patch: github.com"},{"id":148076,"url":"https://github.com/OpenKermit/ckermit/releases/tag/v11.1.515","title":"Release notes: github.com","kind":"release","source":"nvd","publisher":"vendor","text":null,"published_at":null,"relation":"fix","confidence":null,"note":"Release notes: github.com"},{"id":148089,"url":"https://github.com/OpenKermit/ckermit/security/advisories/GHSA-vhrv-7jrq-95qj","title":"Vendor advisory: github.com","kind":"vendor","source":"nvd","publisher":"vendor","text":null,"published_at":"2026-10-31T01:21:24+00:00","relation":"advisory","confidence":null,"note":"Vendor advisory: github.com"},{"id":148098,"url":"https://www.vulncheck.com/advisories/c-kermit-8.0.200-before-11.1.515-path-traversal-via-ftp-mget-recursive","title":"Third-party advisory: www.vulncheck.com","kind":"advisory","source":"nvd","publisher":"research","text":null,"published_at":null,"relation":"advisory","confidence":null,"note":"Third-party advisory: www.vulncheck.com"}],"disclosures":[],"exploit_sources":[],"notice":"Free to read, with fair use of about 60 pages a minute. For higher limits or API access: sales@infrastack.ai"}