[dunfell] dropbear: fix CVE-2021-36369

From: Lee Chee Yang <chee.yang.lee@intel.com>

Signed-off-by: Lee Chee Yang <chee.yang.lee@intel.com>
---
 meta/recipes-core/dropbear/dropbear.inc       |   1 +
 .../dropbear/dropbear/CVE-2021-36369.patch    | 145 ++++++++++++++++++
 2 files changed, 146 insertions(+)
 create mode 100644 meta/recipes-core/dropbear/dropbear/CVE-2021-36369.patch

I'm getting patch fuzz warnings.  Could you refresh the patch and submit a v2?

stdio: WARNING: dropbear-2019.78-r0 do_patch: Fuzz detected:
stdio: WARNING: dropbear-2019.78-r0 do_patch: QA Issue: Patch log
indicates that patches do not apply cleanly. [patch-fuzz]

Thanks!

Steve

On Mon, Dec 5, 2022 at 9:55 PM Lee Chee Yang <chee.yang.lee@intel.com> wrote:
>
> From: Lee Chee Yang <chee.yang.lee@intel.com>
>
> Signed-off-by: Lee Chee Yang <chee.yang.lee@intel.com>
> ---
>  meta/recipes-core/dropbear/dropbear.inc       |   1 +
>  .../dropbear/dropbear/CVE-2021-36369.patch    | 145 ++++++++++++++++++
>  2 files changed, 146 insertions(+)
>  create mode 100644 meta/recipes-core/dropbear/dropbear/CVE-2021-36369.patch
>
> diff --git a/meta/recipes-core/dropbear/dropbear.inc b/meta/recipes-core/dropbear/dropbear.inc
> index 026292230c..0f5e9ba4ac 100644
> --- a/meta/recipes-core/dropbear/dropbear.inc
> +++ b/meta/recipes-core/dropbear/dropbear.inc
> @@ -29,6 +29,7 @@ SRC_URI = "http://matt.ucc.asn.au/dropbear/releases/dropbear-${PV}.tar.bz2 \
>             ${@bb.utils.contains('DISTRO_FEATURES', 'pam', '${PAM_SRC_URI}', '', d)} \
>             ${@bb.utils.contains('PACKAGECONFIG', 'disable-weak-ciphers', 'file://dropbear-disable-weak-ciphers.patch', '', d)} \
>             file://CVE-2020-36254.patch \
> +           file://CVE-2021-36369.patch \
>             "
>
>  PAM_SRC_URI = "file://0005-dropbear-enable-pam.patch \
> diff --git a/meta/recipes-core/dropbear/dropbear/CVE-2021-36369.patch b/meta/recipes-core/dropbear/dropbear/CVE-2021-36369.patch
> new file mode 100644
> index 0000000000..5ff11abdd6
> --- /dev/null
> +++ b/meta/recipes-core/dropbear/dropbear/CVE-2021-36369.patch
> @@ -0,0 +1,145 @@
> +From e9b15a8b1035b62413b2b881315c6bffd02205d4 Mon Sep 17 00:00:00 2001
> +From: Manfred Kaiser <37737811+manfred-kaiser@users.noreply.github.com>
> +Date: Thu, 19 Aug 2021 17:37:14 +0200
> +Subject: [PATCH] added option to disable trivial auth methods (#128)
> +
> +* added option to disable trivial auth methods
> +
> +* rename argument to match with other ssh clients
> +
> +* fixed trivial auth detection for pubkeys
> +
> +[https://github.com/mkj/dropbear/pull/128]
> +Upstream-Status: Backport
> +CVE: CVE-2021-36369
> +Signed-off-by: Chee Yang Lee <chee.yang.lee@intel.com>
> +
> +---
> + cli-auth.c         | 3 +++
> + cli-authinteract.c | 1 +
> + cli-authpasswd.c   | 2 +-
> + cli-authpubkey.c   | 1 +
> + cli-runopts.c      | 7 +++++++
> + cli-session.c      | 1 +
> + runopts.h          | 1 +
> + session.h          | 1 +
> + 8 files changed, 16 insertions(+), 1 deletion(-)
> +
> +diff --git a/cli-auth.c b/cli-auth.c
> +index 2e509e5..6f04495 100644
> +--- a/cli-auth.c
> ++++ b/cli-auth.c
> +@@ -267,6 +267,9 @@ void recv_msg_userauth_success() {
> +       if DROPBEAR_CLI_IMMEDIATE_AUTH is set */
> +
> +       TRACE(("received msg_userauth_success"))
> ++      if (cli_opts.disable_trivial_auth && cli_ses.is_trivial_auth) {
> ++              dropbear_exit("trivial authentication not allowed");
> ++      }
> +       /* Note: in delayed-zlib mode, setting authdone here
> +        * will enable compression in the transport layer */
> +       ses.authstate.authdone = 1;
> +diff --git a/cli-authinteract.c b/cli-authinteract.c
> +index e1cc9a1..f7128ee 100644
> +--- a/cli-authinteract.c
> ++++ b/cli-authinteract.c
> +@@ -114,6 +114,7 @@ void recv_msg_userauth_info_request() {
> +       m_free(instruction);
> +
> +       for (i = 0; i < num_prompts; i++) {
> ++              cli_ses.is_trivial_auth = 0;
> +               unsigned int response_len = 0;
> +               prompt = buf_getstring(ses.payload, NULL);
> +               cleantext(prompt);
> +diff --git a/cli-authpasswd.c b/cli-authpasswd.c
> +index 00fdd8b..a24d43e 100644
> +--- a/cli-authpasswd.c
> ++++ b/cli-authpasswd.c
> +@@ -155,7 +155,7 @@ void cli_auth_password() {
> +
> +       encrypt_packet();
> +       m_burn(password, strlen(password));
> +-
> ++      cli_ses.is_trivial_auth = 0;
> +       TRACE(("leave cli_auth_password"))
> + }
> + #endif        /* DROPBEAR_CLI_PASSWORD_AUTH */
> +diff --git a/cli-authpubkey.c b/cli-authpubkey.c
> +index 42c4e3f..fa01807 100644
> +--- a/cli-authpubkey.c
> ++++ b/cli-authpubkey.c
> +@@ -176,6 +176,7 @@ static void send_msg_userauth_pubkey(sign_key *key, enum signature_type sigtype,
> +               buf_putbytes(sigbuf, ses.writepayload->data, ses.writepayload->len);
> +               cli_buf_put_sign(ses.writepayload, key, sigtype, sigbuf);
> +               buf_free(sigbuf); /* Nothing confidential in the buffer */
> ++              cli_ses.is_trivial_auth = 0;
> +       }
> +
> +       encrypt_packet();
> +diff --git a/cli-runopts.c b/cli-runopts.c
> +index 3654b9a..255b47e 100644
> +--- a/cli-runopts.c
> ++++ b/cli-runopts.c
> +@@ -152,6 +152,7 @@ void cli_getopts(int argc, char ** argv) {
> + #if DROPBEAR_CLI_ANYTCPFWD
> +       cli_opts.exit_on_fwd_failure = 0;
> + #endif
> ++      cli_opts.disable_trivial_auth = 0;
> + #if DROPBEAR_CLI_LOCALTCPFWD
> +       cli_opts.localfwds = list_new();
> +       opts.listen_fwd_all = 0;
> +@@ -889,6 +890,7 @@ static void add_extendedopt(const char* origstr) {
> + #if DROPBEAR_CLI_ANYTCPFWD
> +                       "\tExitOnForwardFailure\n"
> + #endif
> ++                      "\tDisableTrivialAuth\n"
> + #ifndef DISABLE_SYSLOG
> +                       "\tUseSyslog\n"
> + #endif
> +@@ -916,5 +918,10 @@ static void add_extendedopt(const char* origstr) {
> +               return;
> +       }
> +
> ++      if (match_extendedopt(&optstr, "DisableTrivialAuth") == DROPBEAR_SUCCESS) {
> ++              cli_opts.disable_trivial_auth = parse_flag_value(optstr);
> ++              return;
> ++      }
> ++
> +       dropbear_log(LOG_WARNING, "Ignoring unknown configuration option '%s'", origstr);
> + }
> +diff --git a/cli-session.c b/cli-session.c
> +index 5e5af22..afb54a1 100644
> +--- a/cli-session.c
> ++++ b/cli-session.c
> +@@ -165,6 +165,7 @@ static void cli_session_init(pid_t proxy_cmd_pid) {
> +       /* Auth */
> +       cli_ses.lastprivkey = NULL;
> +       cli_ses.lastauthtype = 0;
> ++      cli_ses.is_trivial_auth = 1;
> +
> +       /* For printing "remote host closed" for the user */
> +       ses.remoteclosed = cli_remoteclosed;
> +diff --git a/runopts.h b/runopts.h
> +index 6a4a94c..01201d2 100644
> +--- a/runopts.h
> ++++ b/runopts.h
> +@@ -159,6 +159,7 @@ typedef struct cli_runopts {
> + #if DROPBEAR_CLI_ANYTCPFWD
> +       int exit_on_fwd_failure;
> + #endif
> ++      int disable_trivial_auth;
> + #if DROPBEAR_CLI_REMOTETCPFWD
> +       m_list * remotefwds;
> + #endif
> +diff --git a/session.h b/session.h
> +index fb5b8cb..6706592 100644
> +--- a/session.h
> ++++ b/session.h
> +@@ -316,6 +316,7 @@ struct clientsession {
> +
> +       int lastauthtype; /* either AUTH_TYPE_PUBKEY or AUTH_TYPE_PASSWORD,
> +                                                for the last type of auth we tried */
> ++      int is_trivial_auth;
> +       int ignore_next_auth_response;
> + #if DROPBEAR_CLI_INTERACT_AUTH
> +       int auth_interact_failed; /* flag whether interactive auth can still
> --
> 2.25.1
>
>
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