From bc0ea8b34bb5252d0fcdd146430be65fd869313b Mon Sep 17 00:00:00 2001 From: Volker Lendecke Date: Fri, 20 May 2022 10:55:23 +0200 Subject: [PATCH 1/2] CVE-2022-2127: winbindd: Fix WINBINDD_PAM_AUTH_CRAP length checks With WBFLAG_BIG_NTLMV2_BLOB being set plus lm_resp_len too large you can crash winbind. We don't independently check lm_resp_len sufficiently. Discovered via Coverity ID 1504444 Out-of-bounds access BUG: https://bugzilla.samba.org/show_bug.cgi?id=15072 Signed-off-by: Volker Lendecke --- source3/winbindd/winbindd_pam_auth_crap.c | 31 +++++++++++++++-------- 1 file changed, 21 insertions(+), 10 deletions(-) diff --git a/source3/winbindd/winbindd_pam_auth_crap.c b/source3/winbindd/winbindd_pam_auth_crap.c index 6120522ce3cf..e6a32c7ed79c 100644 --- a/source3/winbindd/winbindd_pam_auth_crap.c +++ b/source3/winbindd/winbindd_pam_auth_crap.c @@ -52,6 +52,9 @@ struct tevent_req *winbindd_pam_auth_crap_send( DATA_BLOB chal = data_blob_null; struct wbint_SidArray *require_membership_of_sid = NULL; NTSTATUS status; + bool lmlength_ok = false; + bool ntlength_ok = false; + bool pwlength_ok = false; req = tevent_req_create(mem_ctx, &state, struct winbindd_pam_auth_crap_state); @@ -115,16 +118,24 @@ struct tevent_req *winbindd_pam_auth_crap_send( fstrcpy(request->data.auth_crap.workstation, lp_netbios_name()); } - if (request->data.auth_crap.lm_resp_len > sizeof(request->data.auth_crap.lm_resp) - || request->data.auth_crap.nt_resp_len > sizeof(request->data.auth_crap.nt_resp)) { - if (!(request->flags & WBFLAG_BIG_NTLMV2_BLOB) || - request->extra_len != request->data.auth_crap.nt_resp_len) { - DBG_ERR("Invalid password length %u/%u\n", - request->data.auth_crap.lm_resp_len, - request->data.auth_crap.nt_resp_len); - tevent_req_nterror(req, NT_STATUS_INVALID_PARAMETER); - return tevent_req_post(req, ev); - } + lmlength_ok = (request->data.auth_crap.lm_resp_len <= + sizeof(request->data.auth_crap.lm_resp)); + + ntlength_ok = (request->data.auth_crap.nt_resp_len <= + sizeof(request->data.auth_crap.nt_resp)); + + ntlength_ok |= + ((request->flags & WBFLAG_BIG_NTLMV2_BLOB) && + (request->extra_len == request->data.auth_crap.nt_resp_len)); + + pwlength_ok = lmlength_ok && ntlength_ok; + + if (!pwlength_ok) { + DBG_ERR("Invalid password length %u/%u\n", + request->data.auth_crap.lm_resp_len, + request->data.auth_crap.nt_resp_len); + tevent_req_nterror(req, NT_STATUS_INVALID_PARAMETER); + return tevent_req_post(req, ev); } state->domain = talloc_strdup(state, request->data.auth_crap.domain); -- 2.40.0 From dd6cd1ea26306115fea42bb457b11c25ef751c4f Mon Sep 17 00:00:00 2001 From: Ralph Boehme Date: Fri, 16 Jun 2023 12:28:47 +0200 Subject: [PATCH 2/2] CVE-2022-2127: ntlm_auth: cap lanmen response length value We already copy at most sizeof(request.data.auth_crap.lm_resp) bytes to the lm_resp buffer, but we don't cap the length indicator. BUG: https://bugzilla.samba.org/show_bug.cgi?id=15072 Signed-off-by: Ralph Boehme --- source3/utils/ntlm_auth.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/source3/utils/ntlm_auth.c b/source3/utils/ntlm_auth.c index 1306951c2a8d..62319ccd5b9d 100644 --- a/source3/utils/ntlm_auth.c +++ b/source3/utils/ntlm_auth.c @@ -576,10 +576,14 @@ NTSTATUS contact_winbind_auth_crap(const char *username, memcpy(request.data.auth_crap.chal, challenge->data, MIN(challenge->length, 8)); if (lm_response && lm_response->length) { + size_t capped_lm_response_len = MIN( + lm_response->length, + sizeof(request.data.auth_crap.lm_resp)); + memcpy(request.data.auth_crap.lm_resp, lm_response->data, - MIN(lm_response->length, sizeof(request.data.auth_crap.lm_resp))); - request.data.auth_crap.lm_resp_len = lm_response->length; + capped_lm_response_len); + request.data.auth_crap.lm_resp_len = capped_lm_response_len; } if (nt_response && nt_response->length) { -- 2.40.0