Backport of: From 259b4f2e1fd01fbc55e569ee0a507afeae34f77c Mon Sep 17 00:00:00 2001 From: Patrick Monnerat Date: Tue, 7 Sep 2021 13:26:42 +0200 Subject: [PATCH] ftp,imap,pop3,smtp: reject STARTTLS server response pipelining If a server pipelines future responses within the STARTTLS response, the former are preserved in the pingpong cache across TLS negotiation and used as responses to the encrypted commands. This fix detects pipelined STARTTLS responses and rejects them with an error. Bug: https://curl.se/docs/CVE-2021-22947.html Upstream-Status: backport from 7.68.0-1ubuntu2.7 Signed-off-by: Mike Crowe CVE: CVE-2021-22947 --- lib/ftp.c | 3 +++ lib/imap.c | 4 +++ lib/pop3.c | 4 +++ lib/smtp.c | 4 +++ tests/data/Makefile.inc | 2 ++ tests/data/test980 | 52 ++++++++++++++++++++++++++++++++++++ tests/data/test981 | 59 +++++++++++++++++++++++++++++++++++++++++ tests/data/test982 | 57 +++++++++++++++++++++++++++++++++++++++ tests/data/test983 | 52 ++++++++++++++++++++++++++++++++++++ 9 files changed, 237 insertions(+) create mode 100644 tests/data/test980 create mode 100644 tests/data/test981 create mode 100644 tests/data/test982 create mode 100644 tests/data/test983 diff --git a/lib/ftp.c b/lib/ftp.c index 91b43d8..31a34e8 100644 --- a/lib/ftp.c +++ b/lib/ftp.c @@ -2670,6 +2670,9 @@ static CURLcode ftp_statemach_act(struct connectdata *conn) case FTP_AUTH: /* we have gotten the response to a previous AUTH command */ + if(pp->cache_size) + return CURLE_WEIRD_SERVER_REPLY; /* Forbid pipelining in response. */ + /* RFC2228 (page 5) says: * * If the server is willing to accept the named security mechanism, diff --git a/lib/imap.c b/lib/imap.c index 9880ce1..0ca700f 100644 --- a/lib/imap.c +++ b/lib/imap.c @@ -946,6 +946,10 @@ static CURLcode imap_state_starttls_resp(struct connectdata *conn, (void)instate; /* no use for this yet */ + /* Pipelining in response is forbidden. */ + if(data->conn->proto.imapc.pp.cache_size) + return CURLE_WEIRD_SERVER_REPLY; + if(imapcode != IMAP_RESP_OK) { if(data->set.use_ssl != CURLUSESSL_TRY) { failf(data, "STARTTLS denied"); diff --git a/lib/pop3.c b/lib/pop3.c index 145b2b4..8a2d52e 100644 --- a/lib/pop3.c +++ b/lib/pop3.c @@ -753,6 +753,10 @@ static CURLcode pop3_state_starttls_resp(struct connectdata *conn, (void)instate; /* no use for this yet */ + /* Pipelining in response is forbidden. */ + if(data->conn->proto.pop3c.pp.cache_size) + return CURLE_WEIRD_SERVER_REPLY; + if(pop3code != '+') { if(data->set.use_ssl != CURLUSESSL_TRY) { failf(data, "STARTTLS denied"); diff --git a/lib/smtp.c b/lib/smtp.c index e187287..66183e2 100644 --- a/lib/smtp.c +++ b/lib/smtp.c @@ -820,6 +820,10 @@ static CURLcode smtp_state_starttls_resp(struct connectdata *conn, (void)instate; /* no use for this yet */ + /* Pipelining in response is forbidden. */ + if(data->conn->proto.smtpc.pp.cache_size) + return CURLE_WEIRD_SERVER_REPLY; + if(smtpcode != 220) { if(data->set.use_ssl != CURLUSESSL_TRY) { failf(data, "STARTTLS denied, code %d", smtpcode); diff --git a/tests/data/Makefile.inc b/tests/data/Makefile.inc index 0fa6799..60e8176 100644 --- a/tests/data/Makefile.inc +++ b/tests/data/Makefile.inc @@ -112,6 +112,8 @@ test945 test946 test947 test948 test949 test950 test951 test952 test953 \ test954 test955 test956 test957 test958 test959 test960 test961 test962 \ test963 test964 test965 test966 test967 test968 test969 \ \ +test980 test981 test982 test983 \ +\ test984 test985 test986 \ \ test1000 test1001 test1002 test1003 test1004 test1005 test1006 test1007 \ diff --git a/tests/data/test980 b/tests/data/test980 new file mode 100644 index 0000000..97567f8 --- /dev/null +++ b/tests/data/test980 @@ -0,0 +1,52 @@ + + + +SMTP +STARTTLS + + + +# +# Server-side + + +CAPA STARTTLS +AUTH PLAIN +REPLY STARTTLS 454 currently unavailable\r\n235 Authenticated\r\n250 2.1.0 Sender ok\r\n250 2.1.5 Recipient ok\r\n354 Enter mail\r\n250 2.0.0 Accepted +REPLY AUTH 535 5.7.8 Authentication credentials invalid + + + +# +# Client-side + + +SSL + + +smtp + + +SMTP STARTTLS pipelined server response + + +mail body + + +smtp://%HOSTIP:%SMTPPORT/%TESTNUMBER --mail-rcpt recipient@example.com --mail-from sender@example.com -u user:secret --ssl --sasl-ir -T - + + + +# +# Verify data after the test has been "shot" + +# 8 is CURLE_WEIRD_SERVER_REPLY + +8 + + +EHLO %TESTNUMBER +STARTTLS + + + diff --git a/tests/data/test981 b/tests/data/test981 new file mode 100644 index 0000000..2b98ce4 --- /dev/null +++ b/tests/data/test981 @@ -0,0 +1,59 @@ + + + +IMAP +STARTTLS + + + +# +# Server-side + + +CAPA STARTTLS +REPLY STARTTLS A002 BAD currently unavailable\r\nA003 OK Authenticated\r\nA004 OK Accepted +REPLY LOGIN A003 BAD Authentication credentials invalid + + + +# +# Client-side + + +SSL + + +imap + + +IMAP STARTTLS pipelined server response + + +imap://%HOSTIP:%IMAPPORT/%TESTNUMBER -T log/upload%TESTNUMBER -u user:secret --ssl + + +Date: Mon, 7 Feb 1994 21:52:25 -0800 (PST) +From: Fred Foobar +Subject: afternoon meeting +To: joe@example.com +Message-Id: +MIME-Version: 1.0 +Content-Type: TEXT/PLAIN; CHARSET=US-ASCII + +Hello Joe, do you think we can meet at 3:30 tomorrow? + + + +# +# Verify data after the test has been "shot" + +# 8 is CURLE_WEIRD_SERVER_REPLY + +8 + + +A001 CAPABILITY +A002 STARTTLS + + + diff --git a/tests/data/test982 b/tests/data/test982 new file mode 100644 index 0000000..9e07cc0 --- /dev/null +++ b/tests/data/test982 @@ -0,0 +1,57 @@ + + + +POP3 +STARTTLS + + + +# +# Server-side + + +CAPA STLS USER +REPLY STLS -ERR currently unavailable\r\n+OK user accepted\r\n+OK authenticated +REPLY PASS -ERR Authentication credentials invalid + + +From: me@somewhere +To: fake@nowhere + +body + +-- + yours sincerely + + + +# +# Client-side + + +SSL + + +pop3 + + +POP3 STARTTLS pipelined server response + + +pop3://%HOSTIP:%POP3PORT/%TESTNUMBER -u user:secret --ssl + + + +# +# Verify data after the test has been "shot" + +# 8 is CURLE_WEIRD_SERVER_REPLY + +8 + + +CAPA +STLS + + + diff --git a/tests/data/test983 b/tests/data/test983 new file mode 100644 index 0000000..300ec45 --- /dev/null +++ b/tests/data/test983 @@ -0,0 +1,52 @@ + + + +FTP +STARTTLS + + + +# +# Server-side + + +REPLY AUTH 500 unknown command\r\n500 unknown command\r\n331 give password\r\n230 Authenticated\r\n257 "/"\r\n200 OK\r\n200 OK\r\n200 OK\r\n226 Transfer complete +REPLY PASS 530 Login incorrect + + + +# Client-side + + +SSL + + +ftp + + +FTP STARTTLS pipelined server response + + +data + to + see +that FTPS +works + so does it? + + +--ssl --ftp-ssl-control ftp://%HOSTIP:%FTPPORT/%TESTNUMBER -T log/test%TESTNUMBER.txt -u user:secret -P %CLIENTIP + + + +# Verify data after the test has been "shot" + +# 8 is CURLE_WEIRD_SERVER_REPLY + +8 + + +AUTH SSL + + +