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CVE-2017-7875: Feh Project: Buffer overflow

CVE-2017-7875 is rated critical with a CVSS v3.0 base score of 9.8 and affects Feh Project. Per its scoring, it can be exploited over the network, without authentication, without any user interaction. The scored impact on confidentiality, integrity and availability is the highest available.

Vulnerability description

In wallpaper.c in feh before v2.18.3, if a malicious client pretends to be the E17 window manager, it is possible to trigger an out-of-boundary heap write while receiving an IPC message. An integer overflow leads to a buffer overflow and/or a double free.

Severity breakdown

CVSS v3.0 9.8: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

• Attack vector: Network. Exploitable remotely over the network, with no need for local or physical access.
• Attack complexity: Low. No special conditions; the attack can be repeated reliably.
• Privileges required: None. No account or prior access is needed.
• User interaction: None. No action from any user is needed.
• Scope: Unchanged. Impact stays within the vulnerable component.
• Confidentiality impact: High. Total loss of confidentiality; sensitive data can be fully disclosed.
• Integrity impact: High. Total loss of integrity; data or system state can be fully modified.
• Availability impact: High. Total loss of availability; the component can be shut down.

Underlying weakness

CWE-787: Out-of-bounds Write

The product writes data past the end, or before the beginning, of the intended buffer.

Affected products

• Feh Project: up to and including 2.18.2

References

• https://feh.finalrewind.org/
• https://github.com/derf/feh/commit/f7a547b7ef8fc8ebdeaa4c28515c9d72e592fb6d
• http://www.securityfocus.com/bid/97689
• https://lists.debian.org/debian-lts-announce/2020/05/msg00021.html
• https://security.gentoo.org/glsa/201707-08