Log in Start free

Vulnerability · Published Sep 2, 2020 · Assigned by mitre

CVE-2020-15811

Medium 6.5

In plain English

A medium-severity security flaw in the squid package (Alpine). There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 4.1% (higher than 91% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS NVD)6.5Medium
Exploit odds (30 days)4.1%top 9.3% of all CVEs
Exploited in the wildNo reportsnot in CISA KEV
Attack toolingNoneno public tooling known

Official description

An issue was discovered in Squid before 4.13 and 5.x before 5.0.4. Due to incorrect data validation, HTTP Request Splitting attacks may succeed against HTTP and HTTPS traffic. This leads to cache poisoning. This allows any client, including browser scripts, to bypass local security and poison the browser cache and any downstream caches with content from an arbitrary source. Squid uses a string search instead of parsing the Transfer-Encoding header to find chunked encoding. This allows an attacker to hide a second request inside Transfer-Encoding: it is interpreted by Squid as chunked and split out into a second request delivered upstream. Squid will then deliver two distinct responses to the client, corrupting any downstream caches.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Alpine:v3.20squid4.13.0-r0ALPINE-CVE-2020-15811
Alpine:v3.21squid4.13.0-r0ALPINE-CVE-2020-15811
Alpine:v3.22squid4.13.0-r0ALPINE-CVE-2020-15811
Alpine:v3.23squid4.13.0-r0ALPINE-CVE-2020-15811
Alpine:v3.24squid4.13.0-r0ALPINE-CVE-2020-15811
Debian:12squid4.13-1DEBIAN-CVE-2020-15811
Debian:13squid4.13-1DEBIAN-CVE-2020-15811
Debian:14squid4.13-1DEBIAN-CVE-2020-15811
Rocky Linux:8libecap0:1.0.1-2.module+el8.4.0+404+316a0dc5RLSA-2020:3623

Affected products (as reported)

VendorProductVersions
n/a n/a n/a

References