[squid-announce] [ADVISORY] SQUID-2021:2 Denial of Service in HTTP Response Processing

[squid3 at treenet.co.nz]

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     Squid Proxy Cache Security Update Advisory SQUID-2021:2
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Advisory ID:       | SQUID-2021:2
Date:              | May 10, 2021
Summary:           | Denial of Service in HTTP Response Processing
Affected versions: | Squid 4.x -> 4.14
                    | Squid 5.x -> 5.0.5
Fixed in version:  | Squid 4.15, 5.0.6
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   <http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-28662>
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Problem Description:

  Due to an input validation bug Squid is vulnerable to a Denial
  of Service against all clients using the proxy.

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Severity:

  This problem allows a remote server to perform Denial of Service
  when delivering HTTP Response messages. The issue trigger is a
  header which can be expected to exist in HTTP traffic without any
  malicious intent by the server.

CVSS Score of 7.9
<https://nvd.nist.gov/vuln-metrics/cvss/v3-calculator?vector=AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H/E:X/RL:O/RC:C/CR:X/IR:X/AR:H/MAV:N/MAC:L/MPR:N/MUI:R/MS:U/MC:N/MI:N/MA:H&version=3.1>

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Updated Packages:

  This bug is fixed by Squid versions 4.15 and 5.0.6.

  In addition, patches addressing this problem for the stable
  releases can be found in our patch archives:

Squid 4:
  
<http://www.squid-cache.org/Versions/v4/changesets/squid-4-b1c37c9e7b30d0efb5e5ccf8200f2a646b9c36f8.patch>

  If you are using a prepackaged version of Squid then please refer
  to the package vendor for availability information on updated
  packages.

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Determining if your version is vulnerable:

  All Squid older than 4.0 are not vulnerable.

  All Squid-4.x up to and including 4.14 are vulnerable.

  All Squid-5.x up to and including 5.0.5 are vulnerable.

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Workaround:

  There are no known workarounds for this vulnerability.

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Contact details for the Squid project:

  For installation / upgrade support on binary packaged versions
  of Squid: Your first point of contact should be your binary
  package vendor.

  If you install and build Squid from the original Squid sources
  then the <squid-users at lists.squid-cache.org> mailing list is your
  primary support point. For subscription details see
  <http://www.squid-cache.org/Support/mailing-lists.html>.

  For reporting of non-security bugs in the latest STABLE release
  the squid bugzilla database should be used
  <http://bugs.squid-cache.org/>.

  For reporting of security sensitive bugs send an email to the
  <squid-bugs at lists.squid-cache.org> mailing list. It's a closed
  list (though anyone can post) and security related bug reports
  are treated in confidence until the impact has been established.

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Credits:

  This vulnerability was discovered by Joshua Rogers of Opera
  Software.

  Fixed by Alex Rousskov of The Measurement Factory.

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Revision history:

  2021-03-08 19:45:14 UTC Initial Report
  2021-03-16 15:45:11 UTC Patch Released
  2021-03-18 01:33:50 UTC CVE Allocation
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