From: Peter Korsgaard Date: Fri, 5 Feb 2021 09:01:01 +0000 (+0100) Subject: package/atftp: add security fix for CVE-2020-6097 X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=5b36e91fda95de313120ab530a07329a1c5d41db;p=buildroot.git package/atftp: add security fix for CVE-2020-6097 Fixed the following security issue: - CVE-2020-6097: An exploitable denial of service vulnerability exists in the atftpd daemon functionality of atftp 0.7.git20120829-3.1+b1. A specially crafted sequence of RRQ-Multicast requests trigger an assert() call resulting in denial-of-service. An attacker can send a sequence of malicious packets to trigger this vulnerability. For more details, see the report: https://talosintelligence.com/vulnerability_reports/TALOS-2020-1029 Signed-off-by: Peter Korsgaard Signed-off-by: Yann E. MORIN --- diff --git a/package/atftp/0004-Fix-for-DoS-issue-CVE-2020-6097.patch b/package/atftp/0004-Fix-for-DoS-issue-CVE-2020-6097.patch new file mode 100644 index 0000000000..fe59325e57 --- /dev/null +++ b/package/atftp/0004-Fix-for-DoS-issue-CVE-2020-6097.patch @@ -0,0 +1,104 @@ +From 96409ef3b9ca061f9527cfaafa778105cf15d994 Mon Sep 17 00:00:00 2001 +From: Peter Kaestle +Date: Wed, 14 Oct 2020 14:02:41 +0200 +Subject: [PATCH] Fix for DoS issue CVE-2020-6097 + +"sockaddr_print_addr" of tftpd can be triggered remotely to call +assert(), which will crash the tftpd daemon. See: +https://talosintelligence.com/vulnerability_reports/TALOS-2020-1029 + +"sockaddr_print_addr" originaly had two features: +1) returning pointer to string of the incoming ip address +2) checking whether ss_family of the connection is supported + +To fix the issue, a separate function "sockaddr_family_supported" is +used to take care of 2) and "sockaddr_print_addr" returns an error +message string for unsupported cases when using 1) insert of calling +assert(). + +[Upstream: + https://sourceforge.net/u/peterkaestle/atftp/ci/96409ef3b9ca061f9527cfaafa778105cf15d994/] +Signed-off-by: Peter Korsgaard +--- + tftp_def.c | 11 ++++++++++- + tftp_def.h | 1 + + tftpd.c | 5 +++++ + tftpd_mtftp.c | 5 +++++ + 4 files changed, 21 insertions(+), 1 deletion(-) + +diff --git a/tftp_def.c b/tftp_def.c +index d457c2a..428a930 100644 +--- a/tftp_def.c ++++ b/tftp_def.c +@@ -180,6 +180,15 @@ int Gethostbyname(char *addr, struct hostent *host) + return OK; + } + ++int ++sockaddr_family_supported(const struct sockaddr_storage *ss) ++{ ++ if (ss->ss_family == AF_INET || ss->ss_family == AF_INET6) ++ return 1; ++ else ++ return 0; ++} ++ + char * + sockaddr_print_addr(const struct sockaddr_storage *ss, char *buf, size_t len) + { +@@ -189,7 +198,7 @@ sockaddr_print_addr(const struct sockaddr_storage *ss, char *buf, size_t len) + else if (ss->ss_family == AF_INET6) + addr = &((const struct sockaddr_in6 *)ss)->sin6_addr; + else +- assert(!"sockaddr_print: unsupported address family"); ++ return "sockaddr_print: unsupported address family"; + return (char *)inet_ntop(ss->ss_family, addr, buf, len); + } + +diff --git a/tftp_def.h b/tftp_def.h +index 0841746..458e310 100644 +--- a/tftp_def.h ++++ b/tftp_def.h +@@ -54,6 +54,7 @@ int print_eng(double value, char *string, int size, char *format); + inline char *Strncpy(char *to, const char *from, size_t size); + int Gethostbyname(char *addr, struct hostent *host); + ++int sockaddr_family_supported(const struct sockaddr_storage *ss); + char *sockaddr_print_addr(const struct sockaddr_storage *, char *, size_t); + #define SOCKADDR_PRINT_ADDR_LEN INET6_ADDRSTRLEN + uint16_t sockaddr_get_port(const struct sockaddr_storage *); +diff --git a/tftpd.c b/tftpd.c +index 0b6f6a5..a7561a5 100644 +--- a/tftpd.c ++++ b/tftpd.c +@@ -644,6 +644,11 @@ void *tftpd_receive_request(void *arg) + } + + #ifdef HAVE_WRAP ++ if (!abort && !sockaddr_family_supported(&data->client_info->client)) ++ { ++ logger(LOG_ERR, "Connection from unsupported network address family refused"); ++ abort = 1; ++ } + if (!abort) + { + /* Verify the client has access. We don't look for the name but +diff --git a/tftpd_mtftp.c b/tftpd_mtftp.c +index d420d10..0032905 100644 +--- a/tftpd_mtftp.c ++++ b/tftpd_mtftp.c +@@ -393,6 +393,11 @@ void *tftpd_mtftp_server(void *arg) + &data_size, data->data_buffer); + + #ifdef HAVE_WRAP ++ if (!sockaddr_family_supported(&sa)) ++ { ++ logger(LOG_ERR, "mtftp: Connection from unsupported network address family refused"); ++ continue; ++ } + /* Verify the client has access. We don't look for the name but + rely only on the IP address for that. */ + sockaddr_print_addr(&sa, addr_str, sizeof(addr_str)); +-- +2.20.1 + diff --git a/package/atftp/atftp.mk b/package/atftp/atftp.mk index cbe05ba7e0..a4b461fda5 100644 --- a/package/atftp/atftp.mk +++ b/package/atftp/atftp.mk @@ -18,6 +18,9 @@ ATFTP_LIBS = -lpthread ATFTP_CONF_ENV = LIBS="$(ATFTP_LIBS)" \ CFLAGS="$(TARGET_CFLAGS) -fgnu89-inline" +# 0004-Fix-for-DoS-issue-CVE-2020-6097.patch +ATFTP_IGNORE_CVES += CVE-2020-6097 + ifeq ($(BR2_PACKAGE_READLINE),y) ATFTP_DEPENDENCIES += readline ATFTP_CONF_OPTS += --enable-libreadline