{"id":"CVE-2025-71450","kind":"vulnerability","aliases":["CVE-2025-71450"],"related":[],"title":"inih: one-byte stack under-read in INI parser via embedded NUL","description":"inih before r63 contains a one-byte stack buffer under-read in ini_parse_stream() in ini.c that allows attackers to read abyss[-1] via an embedded NUL byte after an overlong line. Attackers can supply an INI file or string with a line of at least INI_MAX_LINE-1 bytes followed by a NUL byte, causing undefined behavior reported by memory sanitizers.","summary":"inih is a small C library that parses INI configuration files. Before r63, a crafted line of near-maximum length followed by a NUL byte makes ini_parse_stream() read one byte before a stack buffer, which memory sanitizers flag as undefined behavior.","severity":"medium","cvss":4.8,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["c","embedded","inih","package"],"not_affected_if":["inih-r63-or-later","trusted-input-only"],"how_to_check":"- Find inih in your build: check the vendored copy or package version against the fixed release `r63`.\n- Look for calls to `ini_parse_stream()` or `ini_parse_string()` that feed untrusted INI input.","fix":"- Upgrade inih to `r63` or later (per the linked patch and release notes).","status":"open","published_at":"2026-11-02T15:17:12+00:00","first_seen_at":"2026-11-02T15:24:01+00:00","triaged_at":"2026-11-02T15:26:31+00:00","updated_at":"2026-11-02T15:26:31+00:00","category":"package","confidence":0.7,"triage":{"at":"2026-11-02T15:26:31Z","model":"claude-haiku-5-5","output":{"fix":"- Upgrade inih to `r63` or later (per the linked patch and release notes).","reach":"unknown","title":"inih: one-byte stack under-read in INI parser via embedded NUL","impact":"low","summary":"inih is a small C library that parses INI configuration files. Before r63, a crafted line of near-maximum length followed by a NUL byte makes ini_parse_stream() read one byte before a stack buffer, which memory sanitizers flag as undefined behavior.","audience":"developers","category":"package","nicknames":[],"who_cares":["c","inih","embedded"],"confidence":0.7,"fix_status":"available","needs_auth":"unknown","worst_case":"Out-of-bounds stack read may leak a byte or crash the parser","analyst_note":"","how_to_check":"- Find inih in your build: check the vendored copy or package version against the fixed release `r63`.\n- Look for calls to `ini_parse_stream()` or `ini_parse_string()` that feed untrusted INI input.","plain_action":"","needs_analyst":false,"not_affected_if":["inih-r63-or-later","trusted-input-only"],"who_is_affected":"Applications that embed inih before r63 and parse INI data from untrusted sources are exposed. A one-byte read past a stack buffer is mainly a crash or information-leak risk; programs that only read trusted local config files are less exposed.","user_interaction":"unknown","needs_special_setup":"unknown","severity_if_unknown":"unknown"},"cost_usd":0.00068,"input_tokens":4212,"output_tokens":517,"severity_before":"medium"},"analyst_status":null,"analyst_note":null,"search":"'-1':94C,121C '-2025':16A,19A '-71450':17A,20A 'abyss':93C 'allow':89C 'attack':90C,104C 'behavior':68B,130C 'buffer':61B,78C 'byte':4A,50B,57B,76C,99C,122C,127C 'c':21B,29B 'caus':128C 'configur':34B 'contain':72C 'craft':39B 'cve':15A,18A 'embed':13A,22B,97C 'file':35B,109C 'flag':65B 'follow':46B,123C 'ini':10A,33B,52B,83C,108C,118C 'ini.c':87C 'inih':1A,23B,25B,69C 'least':117C 'length':45B 'librari':30B 'line':40B,103C,114C,120C 'make':51B 'max':119C 'maximum':44B 'memori':63B,133C 'near':43B 'near-maximum':42B 'nul':14A,49B,98C,126C 'one':3A,56B,75C 'one-byt':2A,74C 'overlong':102C 'packag':24B 'pars':32B,53B,84C 'parser':11A 'r63':37B,71C 'read':8A,55B,81C,92C 'report':131C 'sanit':64B,134C 'small':28B 'stack':5A,60B,77C 'stream':54B,85C 'string':111C 'suppli':106C 'undefin':67B,129C 'under-read':6A,79C 'via':12A,95C","nicknames":[],"mitigations":[],"who_affected":"Applications that embed inih before r63 and parse INI data from untrusted sources are exposed. A one-byte read past a stack buffer is mainly a crash or information-leak risk; programs that only read trusted local config files are less exposed.","tier":"C","verified":{},"analyst_revisit_at":null,"fix_status":"available","audience":"developers","plain_action":null,"pkeys":[],"ptokens":[],"labels":["c","embedded","inih","medium","package"],"first_public_at":"2026-11-02T15:17:12+00:00","kev":null,"cvss_vector":"CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:L/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-2025-71450","url":"https://nvd.nist.gov/vuln/detail/CVE-2025-71450","severity":null,"published_at":"2026-11-02T15:17:12+00:00","modified_at":"2026-11-02T15:17:12+00:00","first_seen_at":"2026-11-02T15:24:01+00:00","fetched_at":"2026-11-02T15:24:01+00:00","note":null}],"documents":[{"id":52433,"url":"https://github.com/benhoyt/inih/commit/8e06f6b77b5d4471bdc6d85ada81b67d37354a5c","title":"Patch: github.com","kind":"other","source":"nvd","publisher":"vendor","text":null,"published_at":null,"relation":"fix","confidence":null,"note":"Patch: github.com"},{"id":52434,"url":"https://github.com/benhoyt/inih/releases/tag/r63","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":52435,"url":"https://www.vulncheck.com/advisories/inih-before-r63-stack-buffer-under-read-in-ini-parse-stream-discard-loop","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"}],"notice":"Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai"}