Ubuntu 16.04 LTS / 18.04 LTS : Squid vulnerabilities (USN-4551-1)

Medium Nessus Plugin ID 140919

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VPR Score: 5.9

Synopsis

The remote Ubuntu host is missing one or more security updates.

Description

The remote Ubuntu 16.04 LTS / 18.04 LTS host has packages installed that are affected by multiple vulnerabilities as referenced in the USN-4551-1 advisory.

- An issue was discovered in http/ContentLengthInterpreter.cc in Squid before 4.12 and 5.x before 5.0.3. A Request Smuggling and Poisoning attack can succeed against the HTTP cache. The client sends an HTTP request with a Content-Length header containing +\ - or an uncommon shell whitespace character prefix to the length field-value. (CVE-2020-15049)

- An issue was discovered in Squid before 4.13 and 5.x before 5.0.4. Due to incorrect data validation, HTTP Request Smuggling 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 proxy cache and any downstream caches with content from an arbitrary source. When configured for relaxed header parsing (the default), Squid relays headers containing whitespace characters to upstream servers. When this occurs as a prefix to a Content-Length header, the frame length specified will be ignored by Squid (allowing for a conflicting length to be used from another Content-Length header) but relayed upstream. (CVE-2020-15810)

- 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. (CVE-2020-15811)

- Squid before 4.13 and 5.x before 5.0.4 allows a trusted peer to perform Denial of Service by consuming all available CPU cycles during handling of a crafted Cache Digest response message. This only occurs when cache_peer is used with the cache digests feature. The problem exists because peerDigestHandleReply() livelocking in peer_digest.cc mishandles EOF. (CVE-2020-24606)

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

Solution

Update the affected packages.

See Also

https://ubuntu.com/security/notices/USN-4551-1

Plugin Details

Severity: Medium

ID: 140919

File Name: ubuntu_USN-4551-1.nasl

Version: 1.3

Type: local

Agent: unix

Published: 2020/09/28

Updated: 2020/11/24

Dependencies: 12634

Risk Information

Risk Factor: Medium

VPR Score: 5.9

CVSS Score Source: CVE-2020-15049

CVSS v2.0

Base Score: 6.5

Temporal Score: 4.8

Vector: CVSS2#AV:N/AC:L/Au:S/C:P/I:P/A:P

Temporal Vector: CVSS2#E:U/RL:OF/RC:C

CVSS v3.0

Base Score: 8.8

Temporal Score: 7.7

Vector: CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Temporal Vector: CVSS:3.0/E:U/RL:O/RC:C

Vulnerability Information

CPE: cpe:/o:canonical:ubuntu_linux:16.04:-:lts, cpe:/o:canonical:ubuntu_linux:18.04:-:lts, p-cpe:/a:canonical:ubuntu_linux:squid, p-cpe:/a:canonical:ubuntu_linux:squid-cgi, p-cpe:/a:canonical:ubuntu_linux:squid-common, p-cpe:/a:canonical:ubuntu_linux:squid-purge, p-cpe:/a:canonical:ubuntu_linux:squid3, p-cpe:/a:canonical:ubuntu_linux:squidclient

Required KB Items: Host/cpu, Host/Ubuntu, Host/Ubuntu/release, Host/Debian/dpkg-l

Exploit Ease: No known exploits are available

Patch Publication Date: 2020/09/28

Vulnerability Publication Date: 2020/06/30

Reference Information

CVE: CVE-2020-15049, CVE-2020-15810, CVE-2020-15811, CVE-2020-24606

USN: 4551-1

IAVB: 2020-B-0050