Information disclosure in gd (Alpine package)

1) Information disclosure

EUVDB-ID: #VU11789

Risk: Low

CVSSv4.0: 1.2 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2017-7890

CWE-ID: CWE-200 - Information exposure

Exploit availability: No

Description

The vulnerability allows a remote attacker to obtain potentially sensitive information.

The weakness exists in the GIF decoding function gdImageCreateFromGifCtx in gd_gif_in.c due to it does not zero colorMap arrays before use. A remote attacker can trick the victim into opening a specially crafted GIF image that could use the uninitialized tables to read ~700 bytes from the top of the stack and gain access to potentially sensitive information.

Mitigation

Install update from vendor's website.

Vulnerable software versions

gd (Alpine package): 2.2.4-r0

CPE2.3

• cpe:2.3:o:alpine:gd_alpine_package:2.2.4-r0:*:*:*:*:alpine_linux:*:3.3

External links

https://git.alpinelinux.org/aports/commit/?id=fa666308ab37b32d9aef124a737b59ebd06a1f7a
https://git.alpinelinux.org/aports/commit/?id=c77ede20873cee5072a80b7d96cfdd045cc1bc7f
https://git.alpinelinux.org/aports/commit/?id=d6da87295c4d40896255b08ee5b73d8199e352cb
https://git.alpinelinux.org/aports/commit/?id=0dfd5e85b10c2aba69314b961c7023dcce1d1514
https://git.alpinelinux.org/aports/commit/?id=2163755a312b6f196914d74c863dcc8edfb81e0b

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.