PT-2021-3106 · Squid+9 · Squid+10

Joshua Rogers · Published 2021-05-10 · Updated 2024-06-15 · CVE-2021-31806

Positive Technologies (AI Summary)

CVSS v2.0

6.8

Medium

Base vector

AV:N/AC:L/Au:S/C:N/I:N/A:C

Name of the Vulnerable Software and Affected Versions Squid versions prior to 4.15 Squid versions 5.x prior to 5.0.6

Description The issue is related to a memory-management bug that makes Squid vulnerable to a Denial of Service attack against all clients using the proxy. This can be exploited via HTTP Range request processing. The vulnerability exists due to insufficient checking of user-input data during HTTP Range request processing, allowing a remote attacker to cause a denial of service.

Recommendations For Squid versions prior to 4.15, update to version 4.15 or later. For Squid versions 5.x prior to 5.0.6, update to version 5.0.6 or later. As a temporary workaround, consider restricting access to HTTP Range request processing until a patch is available.

Exploit

Fix

DoS

RCE

Improper Encoding or Escaping of Output

Weakness Enumeration

CWE-20

CWE-116

Related Identifiers

ALSA-2021:4292

ALT-PU-2021-2058

ALT-PU-2021-2829

BDU:2021-02729

CESA-2021_4292

CVE-2021-31806

DLA-2685-1

DSA-4924-1

GHSA-PXWQ-F3QR-W2XF

MGASA-2021-0237

OESA-2021-1240

OPENSUSE-SU-2021:0879-1

OPENSUSE-SU-2021:1961-1

OPENSUSE-SU-2021_0879-1

OPENSUSE-SU-2021_1961-1

OPENSUSE-SU-2024:11403-1

RHSA-2021:4292

RHSA-2021_4292

RLSA-2021:4292

SUSE-SU-2021:1838-1

SUSE-SU-2021:1961-1

USN-4981-1

Affected Products

Alt Linux

Almalinux

Astra Linux

Centos

Linuxmint

Red Hat

Rocky Linux

Squid

Squid Cache

Suse

Ubuntu

References · 138

• 🔥 https://github.com/rapid7/metasploit-framework/blob/master/modules/auxiliary/dos/http/squid_range_dos.rb · Exploit
• https://github.com/squid-cache/squid/security/advisories/GHSA-pxwq-f3qr-w2xf · Patch
• https://osv.dev/vulnerability/USN-4981-1 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2021-33620 · Security Note
• https://linux.oracle.com/errata/ELSA-2021-9465.html · Vendor Advisory
• http://squid-cache.org/Versions/v4/changesets/squid-4-e7cf864f938f24eea8af0692c04d16790983c823.patch · Vendor Advisory
• https://wiki.astralinux.ru/astra-linux-se16-bulletin-20211008SE16 · Vendor Advisory
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/T4EPIWUZDJAXADDHVOPKRBTQHPBR6H66 · Vendor Advisory
• https://ubuntu.com/security/CVE-2021-28651 · Vendor Advisory
• https://osv.dev/vulnerability/SUSE-SU-2021:1961-1 · Vendor Advisory
• https://security-tracker.debian.org/tracker/CVE-2021-31806 · Vendor Advisory
• https://osv.dev/vulnerability/MGASA-2021-0237 · Vendor Advisory
• https://advisories.mageia.org/MGASA-2021-0237.html · Security Note
• https://osv.dev/vulnerability/DLA-2685-1 · Vendor Advisory
• https://errata.rockylinux.org/RLSA-2021:4292 · Vendor Advisory