CVE-2019-2107

CVE-2019-2107

CVE-2019-2107 - looks scary. Still remember Stagefright and PNG bugs vulns .... With CVE-2019-2107 the decoder/codec runs under mediacodec user and with properly "crafted" video (with tiles enabled - ps_pps->i1_tiles_enabled_flag) you can possibly do RCE. The codec affected is HVEC (a.k.a H.265 and MPEG-H Part 2) #exploit #rce #android #stagefright #cve

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More infos

LineageOS (Android):

02-11 20:18:48.238   260   260 D FFmpegExtractor: ffmpeg detected media content as 'video/hevc' with confidence 0.08
02-11 20:18:48.239   260   260 I FFMPEG  : [hevc @ 0xb348f000] Invalid tile widths.
02-11 20:18:48.239   260   260 I FFMPEG  : [hevc @ 0xb348f000] PPS id out of range: 0
02-11 20:18:48.240   260   260 I FFMPEG  : [hevc @ 0xb348f000] Invalid tile widths.
02-11 20:18:48.240   260   260 I FFMPEG  : [hevc @ 0xb348f000] PPS id out of range: 0
02-11 20:18:48.240   260   260 I FFMPEG  : [hevc @ 0xb348f000] Error parsing NAL unit #5.
02-11 20:18:48.240   260   260 I FFMPEG  : [hevc @ 0xb348f000] Invalid tile widths.

mplayer (laptop)

id: 0
[hevc @ 0x7f0bf58a7560]Decoding VPS
[hevc @ 0x7f0bf58a7560]Main profile bitstream
[hevc @ 0x7f0bf58a7560]Decoding SPS
[hevc @ 0x7f0bf58a7560]Main profile bitstream
[hevc @ 0x7f0bf58a7560]Decoding VUI
[hevc @ 0x7f0bf58a7560]Decoding PPS
[hevc @ 0x7f0bf58a7560]Invalid tile widths.
[hevc @ 0x7f0bf58a7560]Decoding SEI
[hevc @ 0x7f0bf58a7560]Skipped PREFIX SEI 5
[hevc @ 0x7f0bf58a7560]PPS id out of range: 0
[hevc @ 0x7f0bf58a7560]Error parsing NAL unit #5.
Error while decoding frame!

This stops it when the tile width is bigger than allowed: https://gitlab.freedesktop.org/gstreamer/meson-ports/ffmpeg/blob/ebf648d490448d511b5fe970d76040169e65ef74/libavcodec/hevc_ps.c#L1526

So the check are there.

On stock/google Andoird I think it will use libhevc, not ffmpeg, when using VideoPlayer.

https://www.droidviews.com/enjoy-hevc-h-265-video-playback-on-android/

I have the google codec:

OMX.google.hevc.decoder

I am wondering however why it does not crash ....

Attaching the video (videopoc.mp4) that should trigger this condition:

if (value >= ps_sps->i2_pic_wd_in_ctb - start)
+                        {
+                            return IHEVCD_INVALID_HEADER;
+                        }

Maybe somebody have more luck.

More infos 2

Whoooo hooo .... made it :)

Proof of concept is in hevc-crash-poc.mp4, other videos are for non andoird players.

Hvec-"fright" is possible. You can own the mobile by viewing a video with payload. In my example I didn't include real payload.

07-13 21:50:59.000  3351  3351 I /system/bin/tombstoned: received crash request for pid 24089
07-13 21:50:59.006 24089 24089 F DEBUG   : *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***
07-13 21:50:59.006 24089 24089 F DEBUG   : Build fingerprint: 'samsung/hero2ltexx/hero2lte:8.0.0/R16NW/G935FXXS4ESC3:user/release-keys'
07-13 21:50:59.006 24089 24089 F DEBUG   : Revision: '9'
07-13 21:50:59.006 24089 24089 F DEBUG   : ABI: 'arm64'
07-13 21:50:59.006 24089 24089 F DEBUG   : pid: 24089, tid: 24089, name: media.extractor  >>> mediaextractor <<<
07-13 21:50:59.006 24089 24089 F DEBUG   : signal 11 (SIGSEGV), code 1 (SEGV_MAPERR), fault addr 0x7ccb800050
07-13 21:50:59.009 24089 24089 F DEBUG   :     x0   00000000ffffff36  x1   0000000000000000  x2   00000000000000f0  x3   0000000000000001
07-13 21:50:59.009 24089 24089 F DEBUG   :     x4   0000000000000001  x5   0000007ccb5df1b8  x6   0000007cc927363e  x7   0000007cc8e7bd04
07-13 21:50:59.009 24089 24089 F DEBUG   :     x8   0000000000004170  x9   0000000000004160  x10  00000000ffffffff  x11  0000007ccb7fbef0
07-13 21:50:59.010 24089 24089 F DEBUG   :     x12  0000007ccb5d3ce0  x13  000000000000001e  x14  0000000000000003  x15  0000000000000001
07-13 21:50:59.010 24089 24089 F DEBUG   :     x16  0000007cc99f5f50  x17  0000007ccb88885c  x18  0000007ccb566225  x19  0000007ccb562020
07-13 21:50:59.010 24089 24089 F DEBUG   :     x20  0000007ccb4f18a0  x21  0000007ccb468c6c  x22  0000000000000000  x23  0000000000000006
07-13 21:50:59.010 24089 24089 F DEBUG   :     x24  000000000000001e  x25  0000000000000094  x26  0000000000004160  x27  0000000000000001
07-13 21:50:59.010 24089 24089 F DEBUG   :     x28  0000007ccb55e750  x29  0000007fd6d39d90  x30  0000007cc99c4438
07-13 21:50:59.010 24089 24089 F DEBUG   :     sp   0000007fd6d39d20  pc   0000007cc99c44c4  pstate 0000000080000000
07-13 21:50:59.013 24089 24089 F DEBUG   : 
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