From c08ca60a60b64bb214288a46ad7822276b38ba4f Mon Sep 17 00:00:00 2001 From: Petr Menšík pemensik@redhat.com Date: Oct 02 2017 15:41:10 +0000 Subject: Security fix, CVE-2017-14495, OOM in DNS response
creation.
Fix out-of-memory Dos vulnerability. An attacker which can send malicious DNS queries to dnsmasq can trigger memory allocations in the add_pseudoheader function The allocated memory is never freed which leads to a DoS through memory exhaustion. dnsmasq is vulnerable only if one of the following option is specified: --add-mac, --add-cpe-id or --add-subnet.
Signed-off-by: Petr Menšík pemensik@redhat.com
---
diff --git a/dnsmasq-2.77-CVE-2017-14495.patch b/dnsmasq-2.77-CVE-2017-14495.patch new file mode 100644 index 0000000..0f793aa --- /dev/null +++ b/dnsmasq-2.77-CVE-2017-14495.patch @@ -0,0 +1,41 @@ +From 51eadb692a5123b9838e5a68ecace3ac579a3a45 Mon Sep 17 00:00:00 2001 +From: Simon Kelley simon@thekelleys.org.uk +Date: Mon, 25 Sep 2017 20:16:50 +0100 +Subject: [PATCH 7/9] Security fix, CVE-2017-14495, OOM in DNS response + creation. + +Fix out-of-memory Dos vulnerability. An attacker which can +send malicious DNS queries to dnsmasq can trigger memory +allocations in the add_pseudoheader function +The allocated memory is never freed which leads to a DoS +through memory exhaustion. dnsmasq is vulnerable only +if one of the following option is specified: +--add-mac, --add-cpe-id or --add-subnet. +--- + src/edns0.c | 8 +++++++- + 1 file changed, 7 insertions(+), 1 deletion(-) + +diff --git a/src/edns0.c b/src/edns0.c +index 95b74ee..89b2692 100644 +--- a/src/edns0.c ++++ b/src/edns0.c +@@ -192,9 +192,15 @@ size_t add_pseudoheader(struct dns_header *header, size_t plen, unsigned char *l + !(p = skip_section(p, + ntohs(header->ancount) + ntohs(header->nscount) + ntohs(header->arcount), + header, plen))) ++ { ++ free(buff); + return plen; ++ } + if (p + 11 > limit) +- return plen; /* Too big */ ++ { ++ free(buff); ++ return plen; /* Too big */ ++ } + *p++ = 0; /* empty name */ + PUTSHORT(T_OPT, p); + PUTSHORT(udp_sz, p); /* max packet length, 512 if not given in EDNS0 header */ +-- +2.9.5 + diff --git a/dnsmasq.spec b/dnsmasq.spec index 3151c8e..41c3607 100644 --- a/dnsmasq.spec +++ b/dnsmasq.spec @@ -30,6 +30,7 @@ Patch3: dnsmasq-2.77-CVE-2017-14492.patch Patch4: dnsmasq-2.77-CVE-2017-14493.patch Patch5: dnsmasq-2.77-CVE-2017-14494.patch Patch6: dnsmasq-2.77-CVE-2017-14496.patch +Patch7: dnsmasq-2.77-CVE-2017-14495.patch
BuildRoot: %{_tmppath}/%{name}-%{version}-%{release}-root-%(%{__id_u} -n)
@@ -70,6 +71,7 @@ query/remove a DHCP server's leases. %patch4 -p1 -b .CVE-2017-14493 %patch5 -p1 -b .CVE-2017-14494 %patch6 -p1 -b .CVE-2017-14496 +%patch7 -p1 -b .CVE-2017-14495
# use /var/lib/dnsmasq instead of /var/lib/misc for file in dnsmasq.conf.example man/dnsmasq.8 man/es/dnsmasq.8 src/config.h; do @@ -163,6 +165,7 @@ rm -rf $RPM_BUILD_ROOT - Security fix, CVE-2017-14493, DHCPv6 - Stack buffer overflow - Security fix, CVE-2017-14494, Infoleak handling DHCPv6 - Security fix, CVE-2017-14496, Integer underflow in DNS response creation +- Security fix, CVE-2017-14495, OOM in DNS response creation
* Wed Oct 19 2016 Pavel Šimerda psimerda@redhat.com - 2.76-2 - Resolves: #1373485 - dns not updated after sleep and resume laptop
https://src.fedoraproject.org/rpms/dnsmasq/c/c08ca60a60b64bb214288a46ad78222...