From 50c9484278c63b958655a717844f0721263939cc Mon Sep 17 00:00:00 2001 From: Daniel Stenberg Date: Thu, 3 Jan 2019 12:59:28 +0100 Subject: [PATCH] ntlm: fix *_type3_message size check to avoid buffer overflow Bug: https://curl.haxx.se/docs/CVE-2019-3822.html Reported-by: Wenxiang Qian CVE-2019-3822 --- lib/vauth/ntlm.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) --- a/lib/vauth/ntlm.c +++ b/lib/vauth/ntlm.c @@ -776,11 +776,14 @@ CURLcode Curl_auth_create_ntlm_type3_mes }); #ifdef USE_NTRESPONSES - if(size < (NTLM_BUFSIZE - ntresplen)) { - DEBUGASSERT(size == (size_t)ntrespoff); - memcpy(&ntlmbuf[size], ptr_ntresp, ntresplen); - size += ntresplen; + /* ntresplen + size should not be risking an integer overflow here */ + if(ntresplen + size > sizeof(ntlmbuf)) { + failf(data, "incoming NTLM message too big"); + return CURLE_OUT_OF_MEMORY; } + DEBUGASSERT(size == (size_t)ntrespoff); + memcpy(&ntlmbuf[size], ptr_ntresp, ntresplen); + size += ntresplen; DEBUG_OUT({ fprintf(stderr, "\n ntresp=");