Advisory: four vulnerabilities found in MikroTik's RouterOS Details ======= Product: MikroTik's RouterOS Vendor URL: https://mikrotik.com/ Vendor Status: no fix yet CVE: CVE-2020-20214, CVE-2020-20222, CVE-2020-20236, CVE-2020-20237 Credit: Qian Chen(@cq674350529) of Qihoo 360 Nirvan Team Product Description ================== RouterOS is the operating system used on the MikroTik's devices, such as switch, router and access point. Description of vulnerabilities ========================== These vulnerabilities were reported to the vendor almost one year ago. And the vendor confirmed these vulnerabilities. However, there is still no fix for them yet. By the way, the three vulnerabilities in sniffer binary are different from each one. 1. CVE-2020-20214 The btest process suffers from an assertion failure vulnerability. There is a reachable assertion in the btest process. By sending a crafted packet, an authenticated remote user can crash the btest process due to assertion failure. Against stable 6.46.5, the poc resulted in the following crash dump. # cat /rw/logs/backtrace.log 2020.06.19-15:51:36.94@0: 2020.06.19-15:51:36.94@0: 2020.06.19-15:51:36.94@0: /nova/bin/btest 2020.06.19-15:51:36.94@0: --- signal=6 -------------------------------------------- 2020.06.19-15:51:36.94@0: 2020.06.19-15:51:36.94@0: eip=0x7772255b eflags=0x00000246 2020.06.19-15:51:36.94@0: edi=0x00fe0001 esi=0x7772a200 ebp=0x7fdcf880 esp=0x7fdcf878 2020.06.19-15:51:36.94@0: eax=0x00000000 ebx=0x0000010f ecx=0x0000010f edx=0x00000006 2020.06.19-15:51:36.94@0: 2020.06.19-15:51:36.94@0: maps: 2020.06.19-15:51:36.94@0: 08048000-08057000 r-xp 00000000 00:0c 1006 /nova/bin/btest 2020.06.19-15:51:36.94@0: 776f4000-77729000 r-xp 00000000 00:0c 964 /lib/libuClibc-0.9.33.2.so 2020.06.19-15:51:36.94@0: 7772d000-77747000 r-xp 00000000 00:0c 960 /lib/libgcc_s.so.1 2020.06.19-15:51:36.94@0: 77748000-77757000 r-xp 00000000 00:0c 944 /lib/libuc++.so 2020.06.19-15:51:36.94@0: 77758000-77775000 r-xp 00000000 00:0c 947 /lib/libucrypto.so 2020.06.19-15:51:36.94@0: 77776000-777c2000 r-xp 00000000 00:0c 946 /lib/libumsg.so 2020.06.19-15:51:36.94@0: 777c8000-777cf000 r-xp 00000000 00:0c 958 /lib/ld-uClibc-0.9.33.2.so 2020.06.19-15:51:36.94@0: 2020.06.19-15:51:36.94@0: stack: 0x7fdd0000 - 0x7fdcf878 2020.06.19-15:51:36.94@0: 00 a0 72 77 00 a0 72 77 b8 f8 dc 7f 77 e0 71 77 06 00 00 00 00 a2 72 77 20 00 00 00 00 00 00 00 2020.06.19-15:51:36.94@0: 16 00 00 00 18 f9 dc 7f b4 f8 dc 7f e4 2a 7c 77 01 00 00 00 e4 2a 7c 77 16 00 00 00 01 00 fe 00 2020.06.19-15:51:36.94@0: 2020.06.19-15:51:36.94@0: code: 0x7772255b 2020.06.19-15:51:36.94@0: 5b 3d 00 f0 ff ff 76 0e 8b 93 cc ff ff ff f7 d8 This vulnerability was initially found in long-term 6.44.5, and it seems that the latest stable version 6.48.2 still suffers from this vulnerability. 2. CVE-2020-20222 The sniffer process suffers from a memory corruption vulnerability. By sending a crafted packet, an authenticated remote user can crash the sniffer process due to NULL pointer dereference. Against stable 6.46.5, the poc resulted in the following crash dump. # cat /rw/logs/backtrace.log 2020.06.19-16:36:18.33@0: 2020.06.19-16:36:18.33@0: 2020.06.19-16:36:18.33@0: /nova/bin/sniffer 2020.06.19-16:36:18.33@0: --- signal=11 -------------------------------------------- 2020.06.19-16:36:18.33@0: 2020.06.19-16:36:18.33@0: eip=0x08050e33 eflags=0x00010206 2020.06.19-16:36:18.33@0: edi=0x08057a24 esi=0x7f85c094 ebp=0x7f85c0c8 esp=0x7f85c080 2020.06.19-16:36:18.33@0: eax=0x00000000 ebx=0x7f85c090 ecx=0x00ff0000 edx=0x08059678 2020.06.19-16:36:18.33@0: 2020.06.19-16:36:18.33@0: maps: 2020.06.19-16:36:18.33@0: 08048000-08056000 r-xp 00000000 00:0c 1034 /nova/bin/sniffer 2020.06.19-16:36:18.33@0: 776ce000-77703000 r-xp 00000000 00:0c 964 /lib/libuClibc-0.9.33.2.so 2020.06.19-16:36:18.33@0: 77707000-77721000 r-xp 00000000 00:0c 960 /lib/libgcc_s.so.1 2020.06.19-16:36:18.33@0: 77722000-77731000 r-xp 00000000 00:0c 944 /lib/libuc++.so 2020.06.19-16:36:18.33@0: 77732000-7773a000 r-xp 00000000 00:0c 950 /lib/libubox.so 2020.06.19-16:36:18.33@0: 7773b000-77787000 r-xp 00000000 00:0c 946 /lib/libumsg.so 2020.06.19-16:36:18.33@0: 7778d000-77794000 r-xp 00000000 00:0c 958 /lib/ld-uClibc-0.9.33.2.so 2020.06.19-16:36:18.33@0: 2020.06.19-16:36:18.33@0: stack: 0x7f85d000 - 0x7f85c080 2020.06.19-16:36:18.33@0: 2c 08 07 08 04 00 fe 08 fe 00 00 00 20 ad 05 08 00 0c 07 08 a0 0b 07 08 af 0b 07 08 04 7a 05 08 2020.06.19-16:36:18.33@0: 08 00 00 00 24 7a 05 08 ff 00 00 00 00 00 00 00 08 c2 85 7f e4 7a 78 77 d8 c0 85 7f e4 7a 78 77 2020.06.19-16:36:18.34@0: 2020.06.19-16:36:18.34@0: code: 0x8050e33 2020.06.19-16:36:18.34@0: 0b 48 0c 89 fa 89 d8 e8 7d f1 ff ff 50 50 53 56 This vulnerability was initially found in long-term 6.44.6, and it seems that the latest stable version 6.48.2 still suffers from this vulnerability. 3. CVE-2020-20236 The sniffer process suffers from a memory corruption vulnerability. By sending a crafted packet, an authenticated remote user can crash the sniffer process due to invalid memory access. Against stable 6.46.5, the poc resulted in the following crash dump. # cat /rw/logs/backtrace.log 2020.06.19-16:58:33.42@0: 2020.06.19-16:58:33.42@0: 2020.06.19-16:58:33.42@0: /nova/bin/sniffer 2020.06.19-16:58:33.42@0: --- signal=11 -------------------------------------------- 2020.06.19-16:58:33.42@0: 2020.06.19-16:58:33.42@0: eip=0x08050dac eflags=0x00010202 2020.06.19-16:58:33.42@0: edi=0x08057a24 esi=0x00000001 ebp=0x7f8df428 esp=0x7f8df3e0 2020.06.19-16:58:33.42@0: eax=0x08073714 ebx=0x08073710 ecx=0x08073704 edx=0x08073714 2020.06.19-16:58:33.42@0: 2020.06.19-16:58:33.42@0: maps: 2020.06.19-16:58:33.42@0: 08048000-08056000 r-xp 00000000 00:0c 1034 /nova/bin/sniffer 2020.06.19-16:58:33.42@0: 77730000-77765000 r-xp 00000000 00:0c 964 /lib/libuClibc-0.9.33.2.so 2020.06.19-16:58:33.42@0: 77769000-77783000 r-xp 00000000 00:0c 960 /lib/libgcc_s.so.1 2020.06.19-16:58:33.42@0: 77784000-77793000 r-xp 00000000 00:0c 944 /lib/libuc++.so 2020.06.19-16:58:33.42@0: 77794000-7779c000 r-xp 00000000 00:0c 950 /lib/libubox.so 2020.06.19-16:58:33.42@0: 7779d000-777e9000 r-xp 00000000 00:0c 946 /lib/libumsg.so 2020.06.19-16:58:33.43@0: 777ef000-777f6000 r-xp 00000000 00:0c 958 /lib/ld-uClibc-0.9.33.2.so 2020.06.19-16:58:33.43@0: 2020.06.19-16:58:33.43@0: stack: 0x7f8e0000 - 0x7f8df3e0 2020.06.19-16:58:33.43@0: 3c ab 05 08 04 00 fe 08 e0 0f 00 00 14 37 07 08 24 7a 05 08 00 00 00 00 18 f4 8d 7f 04 7a 05 08 2020.06.19-16:58:33.43@0: 08 00 00 00 24 7a 05 08 04 00 00 00 00 00 00 00 70 4a 7a 77 e4 9a 7e 77 38 f4 8d 7f e4 9a 7e 77 2020.06.19-16:58:33.43@0: 2020.06.19-16:58:33.43@0: code: 0x8050dac 2020.06.19-16:58:33.43@0: 8b 43 04 83 e0 fc 85 c0 74 1c 8b 4b 14 39 34 08 This vulnerability was initially found in long-term 6.46.3, and it seems that the latest version stable 6.48.2 still suffers from this vulnerability. 4. CVE-2020-20237 The sniffer process suffers from a memory corruption vulnerability. By sending a crafted packet, an authenticated remote user can crash the sniffer process due to invalid memory access. Against stable 6.46.5, the poc resulted in the following crash dump. # cat /rw/logs/backtrace.log 2020.06.19-17:58:43.98@0: 2020.06.19-17:58:43.98@0: 2020.06.19-17:58:43.98@0: /nova/bin/sniffer 2020.06.19-17:58:43.98@0: --- signal=11 -------------------------------------------- 2020.06.19-17:58:43.98@0: 2020.06.19-17:58:43.98@0: eip=0x77712055 eflags=0x00010202 2020.06.19-17:58:43.98@0: edi=0x77720f34 esi=0x77721015 ebp=0x7ff96b38 esp=0x7ff96af8 2020.06.19-17:58:43.98@0: eax=0x77721054 ebx=0x7771f000 ecx=0x77721034 edx=0x77721014 2020.06.19-17:58:43.98@0: 2020.06.19-17:58:43.98@0: maps: 2020.06.19-17:58:43.98@0: 08048000-08056000 r-xp 00000000 00:0c 1034 /nova/bin/sniffer 2020.06.19-17:58:43.98@0: 776e9000-7771e000 r-xp 00000000 00:0c 964 /lib/libuClibc-0.9.33.2.so 2020.06.19-17:58:43.98@0: 77722000-7773c000 r-xp 00000000 00:0c 960 /lib/libgcc_s.so.1 2020.06.19-17:58:43.98@0: 7773d000-7774c000 r-xp 00000000 00:0c 944 /lib/libuc++.so 2020.06.19-17:58:43.98@0: 7774d000-77755000 r-xp 00000000 00:0c 950 /lib/libubox.so 2020.06.19-17:58:43.98@0: 77756000-777a2000 r-xp 00000000 00:0c 946 /lib/libumsg.so 2020.06.19-17:58:43.98@0: 777a8000-777af000 r-xp 00000000 00:0c 958 /lib/ld-uClibc-0.9.33.2.so 2020.06.19-17:58:43.98@0: 2020.06.19-17:58:43.98@0: stack: 0x7ff97000 - 0x7ff96af8 2020.06.19-17:58:43.98@0: 00 f0 71 77 00 0f 72 77 30 00 00 00 00 00 00 00 38 b2 05 08 34 0f 72 77 04 00 00 00 00 0f 72 77 2020.06.19-17:58:43.98@0: 20 00 00 00 1b 7b 71 77 e8 f1 71 77 98 00 00 00 01 00 00 00 ec c4 74 77 74 a1 05 08 f8 6b f9 7f 2020.06.19-17:58:43.98@0: 2020.06.19-17:58:43.98@0: code: 0x77712055 2020.06.19-17:58:43.98@0: 89 14 10 eb bc 8b 93 a4 ff ff ff 8b 7d e0 8b 42 Interestingly, the same poc resulted in another different crash dump(SIGABRT) against stable 6.48.2. # cat /rw/logs/backtrace.log 2021.05.07-16:02:37.25@0: 2021.05.07-16:02:37.25@0: 2021.05.07-16:02:37.25@0: /nova/bin/sniffer 2021.05.07-16:02:37.25@0: --- signal=6 -------------------------------------------- 2021.05.07-16:02:37.25@0: 2021.05.07-16:02:37.25@0: eip=0x776f255b eflags=0x00000246 2021.05.07-16:02:37.25@0: edi=0x0805aca8 esi=0x776fa200 ebp=0x7f97def8 esp=0x7f97def0 2021.05.07-16:02:37.25@0: eax=0x00000000 ebx=0x000000b6 ecx=0x000000b6 edx=0x00000006 2021.05.07-16:02:37.25@0: 2021.05.07-16:02:37.25@0: maps: 2021.05.07-16:02:37.25@0: 08048000-08056000 r-xp 00000000 00:0c 1036 /nova/bin/sniffer 2021.05.07-16:02:37.25@0: 776c4000-776f9000 r-xp 00000000 00:0c 966 /lib/libuClibc-0.9.33.2.so 2021.05.07-16:02:37.25@0: 776fd000-77717000 r-xp 00000000 00:0c 962 /lib/libgcc_s.so.1 2021.05.07-16:02:37.25@0: 77718000-77727000 r-xp 00000000 00:0c 945 /lib/libuc++.so 2021.05.07-16:02:37.25@0: 77728000-77730000 r-xp 00000000 00:0c 951 /lib/libubox.so 2021.05.07-16:02:37.25@0: 77731000-7777d000 r-xp 00000000 00:0c 947 /lib/libumsg.so 2021.05.07-16:02:37.25@0: 77783000-7778a000 r-xp 00000000 00:0c 960 /lib/ld-uClibc-0.9.33.2.so 2021.05.07-16:02:37.25@0: 2021.05.07-16:02:37.25@0: stack: 0x7f97f000 - 0x7f97def0 2021.05.07-16:02:37.25@0: 00 a0 6f 77 00 a0 6f 77 30 df 97 7f 77 e0 6e 77 06 00 00 00 00 a2 6f 77 20 00 00 00 00 00 00 00 2021.05.07-16:02:37.25@0: 26 2b 6f 77 00 a0 6f 77 28 df 97 7f 21 2c 6f 77 e8 a1 6f 77 00 a0 6f 77 00 bf 6f 77 a8 ac 05 08 2021.05.07-16:02:37.25@0: 2021.05.07-16:02:37.25@0: code: 0x776f255b 2021.05.07-16:02:37.25@0: 5b 3d 00 f0 ff ff 76 0e 8b 93 cc ff ff ff f7 d8 This vulnerability was initially found in long-term 6.46.3, and it seems that the latest stable version 6.48.2 suffers from an assertion failure vulnerability when running the same poc. Solution ======== No upgrade firmware available yet References ========== [1] https://mikrotik.com/download/changelogs/stable-release-tree