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advisory:2020-05-06-1 [2020/05/06 09:24] – created ldiradvisory:2020-05-06-1 [2020/05/18 08:53] – [MITIGATIONS] fix version zorun
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-Placeholder-1 whilst I work out how this works+ 
 +====== Security Advisory 2020-05-06-1 - umdns out-of-bounds reads of heap data and possible buffer overflow (CVE-2020-11750) ====== 
 + 
 +==== DESCRIPTION ==== 
 + 
 +umdns in OpenWrt through 19.07.2 has potential for out-of-bounds reads of heap data and possible buffer overflow.  We have not been made aware of any exploits at this time, however users are advised to update umdnsd package to umdns_2020-04-25-cdac0460-1 or later. 
 + 
 +[[https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2020-11750|CVE-2020-11750]] has been assigned to this issue. 
 +==== REQUIREMENTS ==== 
 + 
 +The ''umdns'' package is not part of the default package set: [[:downloads|official OpenWrt images provided for download]] do not contain ''umdns''. However, third-party images based on OpenWrt may contain ''umdns'' by default. 
 + 
 +In order to exploit this vulnerability, a vulnerable version of the ''umdns'' package needs to be installed on the OpenWrt device. A malicious attacker in the same local network as the OpenWrt device would then need to send a specially crafted mDNS packet. 
 +==== MITIGATIONS ==== 
 + 
 +To fix this issue, update the affected umdns package using the command below. 
 + 
 +   opkg update; opkg upgrade umdns 
 + 
 +The fix is contained in the following and later versions: 
 + 
 +  * OpenWrt master: 2020-04-25-cdac0460-1 [[https://git.openwrt.org/533da61ac630|reboot-13026-g533da61ac630]] and [[https://git.openwrt.org/9f7c8ed0786b|reboot-13071-g9f7c8ed078]] 
 +  * OpenWrt 19.07:  2020-04-25-cdac0460-1 [[https://git.openwrt.org/b71c7c261bd5|v19.07.2-62-gb71c7c261bd5]] and [[https://git.openwrt.org/4e5a29827fbd|v19.07.2-67-g4e5a29827fbd]] 
 +  * OpenWrt 18.06:  2020-04-25-cdac0460-1 [[https://git.openwrt.org/b07624342654|v18.06.8-19-gb076243426]] and [[https://git.openwrt.org/77063bb76ea7|v18.06.8-20-g77063bb76ea7]] 
 + 
 +==== AFFECTED VERSIONS ==== 
 + 
 +To our knowledge, OpenWrt versions 18.06.0 to 18.06.8 and versions 19.07.0 to 
 +19.07.2 are affected.  The fixed packages will be integrated in the upcoming 
 +OpenWrt 18.06.9 and OpenWrt 19.07.3 releases.  Older versions of OpenWrt (e.g. 
 +OpenWrt 15.05 and LEDE 17.01) are end of life and not supported any more. 
 + 
 +==== CREDITS ==== 
 + 
 +This issue was identified by Guido Vranken using ForAllSecure Mayhem and code fix 
 +was implemented by Kevin Darbyshire-Bryant with assistance from Guido Vranken.
  • Last modified: 2020/05/19 10:44
  • by zorun