{"cve":"CVE-2017-1000257","nvd":{"published":"2017-10-31T21:29:00.203","modified":"2026-06-17T00:59:00.403","status":"Modified","description":"An IMAP FETCH response line indicates the size of the returned data, in number of bytes. When that response says the data is zero bytes, libcurl would pass on that (non-existing) data with a pointer and the size (zero) to the deliver-data function. libcurl's deliver-data function treats zero as a magic number and invokes strlen() on the data to figure out the length. The strlen() is called on a heap based buffer that might not be zero terminated so libcurl might read beyond the end of it into whatever memory lies after (or just crash) and then deliver that to the application as if it was actually downloaded.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H","score":9.1},"cwes":["CWE-119"],"references":["http://www.debian.org/security/2017/dsa-4007","http://www.securityfocus.com/bid/101519","http://www.securitytracker.com/id/1039644","https://access.redhat.com/errata/RHSA-2017:3263","https://access.redhat.com/errata/RHSA-2018:2486"],"products":["debian:debian_linux","haxx:libcurl"],"source":"nvd","synced_at":"2026-10-19T20:47:01.408438353+00:00"},"epss":{"cve":"CVE-2017-1000257","score":0.06224,"percentile":0.93537,"date":"2026-10-31"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}