QR-MANIA

Proof of flag 

CTF{2b2e8580cdf35896d75bfc4b1bafff6ee90f6c525da3b9a26dd7726bf2171396}

Summary of the vulnerabilities identified

Inspecting the pcap file with wireshark I found HTTP responses with png images, each one containing a qr code, which decodes to a single character. The position of each character is inside the exif data of the corresponding image.

Proof of solving

Extract HTTP objects with wireshark from the provided .pcap file:

Among the extracted resources, the following .png files can be found:

Each one corresponds to a character in the flag

The order of the characters is contained in the EXIF data of the images

~/D/d/q/resources > exiftool *.png | xargs -n1 grep -i 'file name\|comment'
File Name                       : ajxxcwfgozxpbhnauore.png
Comment                         : 20/69
File Name                       : avudtreighimhcgmwape.png
Comment                         : 39/69
File Name                       : biuwfrwgdocdypyliqyt.png
Comment                         : 27/69
File Name                       : bynatxrryamhwwhmmroj.png
Comment                         : 46/69
File Name                       : cllzodvnyvvmbppaktsd.png
Comment                         : 44/69
File Name                       : czguxctbmqgfgxhvnwzr.png
Comment                         : 69/69
File Name                       : dfhwcysjjnrnhfziizlr.png
Comment                         : 56/69
File Name                       : dglakvmqmabxcqlpgbjb.png
Comment                         : 45/69
File Name                       : dhqclnghhlrjxjmhjzon.png
Comment                         : 54/69
File Name                       : dmdkaosivnyzxyzmglai.png
Comment                         : 65/69

Convert the images into monochrome and decode them with the pyzbar library