CVE-2017-11155

published 2017-08-08

CVE-2017-11155: An information exposure vulnerability in index.php in Synology Photo Station before 6.7.3-3432 and 6.3-2967 allows remote attackers to obtain sensitive system…

Priority P2 63 high 7.5 CVSS 3.0

AV N AC L PR N UI N S U C H I N A N

EXPLOIT

An information exposure vulnerability in index.php in Synology Photo Station before 6.7.3-3432 and 6.3-2967 allows remote attackers to obtain sensitive system information via unspecified vectors.

Affected

3 ranges

Vendor	Product	Version range	Fixed in
synology	photo_station	<= 6.7.2-3429	—
synology	photo_station	—	—
synology	synology_photo_station	—	—

Detection & IOCs extracted from sources · hover to see the quote

url /photo/include/synotheme_upload.php↗

url /photo/include/file_upload.php↗

url /photo/admin/general_setting.php↗

url /photo/PixlrEditorHandler.php↗

url /photo/facebook/exploit.php↗

path /../../../../../var/packages/PhotoStation/etc/blog/photo_custom_preview_logo.png↗

path /../../../../../var/services/photo/@eaDir/SYNOPHOTO_THEME_DIR/photo_custom_preview_logo.png↗

path /volume1/@appstore/PhotoStation/photo/facebook/exploit↗

• → POST request to synotheme_upload.php with action=logo_upload and a file disguised as a .jpg containing a serialized PHP session string — indicates the first stage of the exploit chain (arbitrary file upload). ↗
• → POST to file_upload.php with a path-traversal 'session' parameter pointing to the previously uploaded fake session file — indicates the second stage (fake authentication via session file). ↗
• → POST to PixlrEditorHandler.php with action=save, a base64-encoded PHP payload in 'image', type=php, and a base64-encoded path traversal in 'path' — indicates the third stage (webshell drop via image handler abuse). ↗
• → GET request to /photo/facebook/exploit.php indicates execution of the dropped webshell — monitor for unexpected PHP file creation and access under the PhotoStation facebook/ directory. ↗
• → Process execution context uid=138862(PhotoStation) gid=138862(PhotoStation) is the expected post-exploitation identity — alert on unexpected child processes spawned under this UID. ↗
• → The exploit uses data:// stream wrapper with base64 encoding in the 'image' POST parameter to PixlrEditorHandler.php — detect 'data://text/plain;base64,' in POST bodies to this endpoint. ↗

• · The path traversal session payload has two variants depending on the Photo Station version — defenders should monitor both traversal paths. ↗

CVSS provenance

nvd v3.0 7.5 HIGH CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

nvd v2.0 5.0 MEDIUM AV:N/AC:L/Au:N/C:P/I:N/A:N

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