Seccon 2015 Sunrise Writeup

LeeDoHyun · March 29, 2020

문제 설명은 대충 이렇습니다.

Find the flag in this file.
sunrise.zip

ファイルからflagをさがせ.
sunrise.zip

이미지를 다운로드 받고 exiftool로 보면

ExifTool Version Number         : 11.85
File Name                       : sunrise.png
Directory                       : .
File Size                       : 11 MB
File Modification Date/Time     : 2015:11:23 17:36:40+09:00
File Access Date/Time           : 2020:03:29 17:46:53+09:00
File Inode Change Date/Time     : 2020:03:29 17:46:24+09:00
File Permissions                : rw-rw-r--
File Type                       : PNG
File Type Extension             : png
MIME Type                       : image/png
Image Width                     : 3024
Image Height                    : 4032
Bit Depth                       : 8
Color Type                      : RGB with Alpha
Compression                     : Deflate/Inflate
Filter                          : Adaptive
Interlace                       : Noninterlaced
SRGB Rendering                  : Perceptual
Gamma                           : 2.2
Pixels Per Unit X               : 3780
Pixels Per Unit Y               : 3780
Pixel Units                     : meters
Source                          : iPhone 6s
Modify Date                     : 2015:11:23 17:07:55
Creation Time                   : 2015:11:13 06:14:59
Image Size                      : 3024x4032
Megapixels                      : 12.2

아래 사진의 부분을 수정해주면 크기를 조정할 수 있습니다. 세로의 길이를 조금더 땡겨주면 플래그가 뜹니다.

flag : SECCON{Metadata_modification_is_used_for_imformation_hiding.}

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