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Fencer Vulns
high 7.5

CVE-2016-2570 json

The Edge Side Includes (ESI) parser in Squid 3.x before 3.5.15 and 4.x before 4.0.7 does not check buffer limits during XML parsing, which…

published 2016-02-27 10 y ago modified 2026-06-17 4 mo ago also EUVD-2016-3644

cvss
7.5
version 3.0, NVD
cisa kev
Not listed
not in CISA's catalog
epss
9.0%
EPSS 9.0% chance of exploitation in 30 days, percentile 95%
public exploits
0
none known

Summary

The Edge Side Includes (ESI) parser in Squid 3.x before 3.5.15 and 4.x before 4.0.7 does not check buffer limits during XML parsing, which allows remote HTTP servers to cause a denial of service (assertion failure and daemon exit) via a crafted XML document, related to esi/CustomParser.cc and esi/CustomParser.h.

Patch / fix

  • squid3 Ubuntu 16.04 LTS 3.5.12-1ubuntu7.5

ubuntu advisories UBUNTU-CVE-2016-2570

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • squid RHEL 7 7:3.5.20-2.el7
  • squid-sysvinit RHEL 7 7:3.5.20-2.el7
  • squid-migration-script RHEL 7 7:3.5.20-2.el7

red hat advisories RHSA-2016:2600

  • squid3 SLES for SAP 11 SP4, SLES 11 SP4 3.1.23-8.16.30.1
  • squid SLES for SAP 12 SP1, SLES 12 SP1 3.3.14-20.2

suse advisories SUSE-SU-2016:2089-1SUSE-SU-2016:2008-1

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2016-2570 updated cvss 5.0

squid: some code paths fail to check bounds in string object

  • Red Hat Enterprise Linux 5 squid Red Hat Enterprise Linux 6 squid, squid34
    affected: no fix planned “Will not fix”
  • Red Hat Enterprise Linux Server (v. 7) squid 3.5.20-2.el7, squid-migration-script 3.5.20-2.el7 Red Hat Enterprise Linux Server Optional (v. 7) squid-sysvinit 3.5.20-2.el7 Red Hat Enterprise Linux Workstation (v. 7) squid 3.5.20-2.el7, squid-migration-script 3.5.20-2.el7 Red Hat Enterprise Linux Workstation Optional (v. 7) squid-sysvinit 3.5.20-2.el7
    fixed: vendor fix RHSA-2016:2600

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

8.95% chance of exploitation in the next 30 days, higher than 95% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
NVD 3.0 7.5 CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
NVD 2.0 5.0 AV:N/AC:L/Au:N/C:N/I:N/A:P

Classification

Weakness
  • CWE-20 Improper Input Validation

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.