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CVE-2017-8807: Varnish Cache: Information disclosure

CVE-2017-8807 is rated critical with a CVSS v3.1 base score of 9.1 and affects Varnish Cache, along with 2 other products in NVD’s configuration data. Per its scoring, it can be exploited over the network, without authentication, without any user interaction.

Vulnerability description

vbf_stp_error in bin/varnishd/cache/cache_fetch.c in Varnish HTTP Cache 4.1.x before 4.1.9 and 5.x before 5.2.1 allows remote attackers to obtain sensitive information from process memory because a VFP_GetStorage buffer is larger than intended in certain circumstances involving -sfile Stevedore transient objects.

Severity breakdown

CVSS v3.1 9.1: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/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: None. No loss of integrity.
Availability impact: High. Total loss of availability; the component can be shut down.

Underlying weakness

CWE-119: Improper Restriction of Operations within the Bounds of a Memory Buffer

The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary.

Affected products

Varnish Cache: from 4.1.0 before 4.1.9
Varnish Cache Project: from 5.0.0 before 5.2.1
Debian Linux: 9.0