{"id":"CURL-CVE-2017-1000100","summary":"TFTP sends more than buffer size","details":"When doing a TFTP transfer and curl/libcurl is given a URL that contains a\nlong filename (longer than about 515 bytes), the filename is truncated to fit\nwithin the buffer boundaries, but the buffer size is still wrongly updated\nto use the original length. This too large value is then used in the\n`sendto()` call, making curl attempt to send more data than what is actually\nput into the buffer. The `sendto()` function then reads beyond the end of the\nheap based buffer.\n\nA malicious HTTP(S) server could redirect a vulnerable libcurl-using client to\na crafted TFTP URL (if the client has not restricted which protocols it allows\nredirects to) and trick it to send private memory contents to a remote server\nover UDP. Limit curl's redirect protocols with `--proto-redir` and libcurl's\nwith `CURLOPT_REDIR_PROTOCOLS`.","aliases":["CVE-2017-1000100"],"modified":"2025-11-12T00:50:45Z","published":"2017-08-09T08:00:00Z","database_specific":{"URL":"https://curl.se/docs/CVE-2017-1000100.json","package":"curl","last_affected":"7.54.1","CWE":{"id":"CWE-126","desc":"Buffer Over-read"},"severity":"High","affects":"both","www":"https://curl.se/docs/CVE-2017-1000100.html"},"affected":[{"ranges":[{"type":"SEMVER","events":[{"introduced":"7.15.0"},{"fixed":"7.55.0"}]},{"type":"GIT","repo":"https://github.com/curl/curl.git","events":[{"introduced":"56d9624b566ac15ffb4b4b6eef220a5000b767e0"},{"fixed":"358b2b131ad6c095696f20dcfa62b8305263f898"}]}],"versions":["7.54.1","7.54.0","7.53.1","7.53.0","7.52.1","7.52.0","7.51.0","7.50.3","7.50.2","7.50.1","7.50.0","7.49.1","7.49.0","7.48.0","7.47.1","7.47.0","7.46.0","7.45.0","7.44.0","7.43.0","7.42.1","7.42.0","7.41.0","7.40.0","7.39.0","7.38.0","7.37.1","7.37.0","7.36.0","7.35.0","7.34.0","7.33.0","7.32.0","7.31.0","7.30.0","7.29.0","7.28.1","7.28.0","7.27.0","7.26.0","7.25.0","7.24.0","7.23.1","7.23.0","7.22.0","7.21.7","7.21.6","7.21.5","7.21.4","7.21.3","7.21.2","7.21.1","7.21.0","7.20.1","7.20.0","7.19.7","7.19.6","7.19.5","7.19.4","7.19.3","7.19.2","7.19.1","7.19.0","7.18.2","7.18.1","7.18.0","7.17.1","7.17.0","7.16.4","7.16.3","7.16.2","7.16.1","7.16.0","7.15.5","7.15.4","7.15.3","7.15.2","7.15.1","7.15.0"],"database_specific":{"vanir_signatures":[{"signature_type":"Line","deprecated":false,"signature_version":"v1","digest":{"line_hashes":["299649190253636648298373704767072212028","295307249874644216177103258783560139928","83874492656159097150290477829949816860","270941083274010498415793508909327083905"],"threshold":0.9},"source":"https://github.com/curl/curl.git/commit/358b2b131ad6c095696f20dcfa62b8305263f898","id":"CURL-CVE-2017-1000100-072906fe","target":{"file":"lib/tftp.c"}},{"signature_type":"Function","deprecated":false,"signature_version":"v1","digest":{"length":2738,"function_hash":"279178995567361826597018327790682454261"},"source":"https://github.com/curl/curl.git/commit/358b2b131ad6c095696f20dcfa62b8305263f898","id":"CURL-CVE-2017-1000100-c9641619","target":{"function":"tftp_send_first","file":"lib/tftp.c"}}],"source":"https://curl.se/docs/CURL-CVE-2017-1000100.json"}}],"schema_version":"1.7.3","credits":[{"name":"Even Rouault","type":"FINDER"},{"name":"Daniel Stenberg","type":"REMEDIATION_DEVELOPER"}]}