HIGH
squid: SIGSEGV in ESIContext response handling
Published May 10, 2016
7.5
HIGHCVSS 3.0
EPSS 23.11%
Description
Double free vulnerability in Esi.cc in Squid 3.x before 3.5.18 and 4.x before 4.0.10 allows remote servers to cause a denial of service (crash) via a crafted Edge Side Includes (ESI) response.
Affected products
No data.
Configuration 1
OR
- 3.0
- 3.1
- 3.1.0.1
- 3.1.0.2
- 3.1.0.3
- 3.1.0.4
- 3.1.0.5
- 3.1.0.6
- 3.1.0.7
- 3.1.0.8
- 3.1.0.9
- 3.1.0.10
- 3.1.0.11
- 3.1.0.12
- 3.1.0.13
- 3.1.0.14
- 3.1.0.15
- 3.1.0.16
- 3.1.0.17
- 3.1.0.18
- 3.1.1
- 3.1.2
- 3.1.3
- 3.1.4
- 3.1.5
- 3.1.5.1
- 3.1.6
- 3.1.7
- 3.1.8
- 3.1.9
- 3.1.10
- 3.1.11
- 3.1.12
- 3.1.12.1
- 3.1.12.2
- 3.1.12.3
- 3.1.13
- 3.1.14
- 3.1.15
- 3.1.16
- 3.1.17
- 3.1.18
- 3.1.19
- 3.1.20
- 3.1.21
- 3.1.22
- 3.2.0.1
- 3.2.0.2
- 3.2.0.3
- 3.2.0.4
- 3.2.0.5
- 3.2.0.6
- 3.2.0.7
- 3.2.0.8
- 3.2.0.9
- 3.2.0.10
- 3.2.0.11
- 3.2.0.12
- 3.2.0.13
- 3.2.0.14
- 3.2.0.15
- 3.2.0.16
- 3.2.0.17
- 3.2.0.18
- 3.2.0.19
- 3.2.1
- 3.2.2
- 3.2.3
- 3.2.4
- 3.2.5
- 3.2.6
- 3.2.7
- 3.2.8
- 3.2.9
- 3.2.10
- 3.2.11
- 3.2.12
- 3.2.13
- 3.3.0
- 3.3.0.1
- 3.3.0.2
- 3.3.0.3
- 3.3.1
- 3.3.2
- 3.3.3
- 3.3.4
- 3.3.5
- 3.3.6
- 3.3.7
- 3.3.8
- 3.3.9
- 3.3.10
- 3.3.11
- 3.3.12
- 3.3.13
- 3.3.14
- 3.4.0.1
- 3.4.0.2
- 3.4.0.3
- 3.4.1
- 3.4.2
- 3.4.3
- 3.4.4
- 3.4.4.1
- 3.4.4.2
- 3.4.8
- 3.4.9
- 3.4.10
- 3.4.11
- 3.4.12
- 3.4.13
- 3.4.14
- 3.5.0.1
- 3.5.0.2
- 3.5.0.3
- 3.5.0.4
- 3.5.1
- 3.5.2
- 3.5.3
- 3.5.4
- 3.5.5
- 3.5.6
- 3.5.7
- 3.5.8
- 3.5.9
- 3.5.10
- 3.5.11
- 3.5.12
- 3.5.13
- 3.5.14
- 3.5.15
- 3.5.16
- 3.5.17
Configuration 2
OR
- 4.0.1
- 4.0.2
- 4.0.3
- 4.0.4
- 4.0.5
- 4.0.6
- 4.0.7
- 4.0.8
- 4.0.9
Configuration 4
OR
- 12.04
- 14.04
- 15.10
- 16.04
No data.
Red Hat Enterprise Linux 6
squid-7:3.1.23-16.el6_8.4
Fixed · RHSA-2016:1138
Red Hat Enterprise Linux 6
squid34-7:3.4.14-9.el6_8.3
Fixed · RHSA-2016:1140
Red Hat Enterprise Linux 7
squid-7:3.3.8-26.el7_2.3
Fixed · RHSA-2016:1139
Red Hat Enterprise Linux 5
squid
Not affected
| Product | Package | State | Advisory |
|---|---|---|---|
| Red Hat Enterprise Linux 6 | squid-7:3.1.23-16.el6_8.4 | Fixed | RHSA-2016:1138 |
| Red Hat Enterprise Linux 6 | squid34-7:3.4.14-9.el6_8.3 | Fixed | RHSA-2016:1140 |
| Red Hat Enterprise Linux 7 | squid-7:3.3.8-26.el7_2.3 | Fixed | RHSA-2016:1139 |
| Red Hat Enterprise Linux 5 | squid | Not affected | n/a |
No package ranges for this CVE.
Remediation
No remediation recorded yet.
Metrics
No CVSS v4.0 score for this CVE.
No CVSS v3.1 score for this CVE.
7.5 HIGH NVD
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Attack Vector Network
Attack Complexity Low
Privileges Required None
User Interaction None
Scope Unchanged
Confidentiality Impact None
Integrity Impact None
Availability Impact High
5.0 MEDIUM NVD
AV:N/AC:L/Au:N/C:N/I:N/A:P
Access Vector Network
Access Complexity Low
Authentication None
Confidentiality Impact None
Integrity Impact None
Availability Impact Partial
This CVE is not in the KEV list.
No CISA SSVC assessment for this CVE yet.
23.11% 0.23112
Estimated probability of exploitation in the wild in the next 30 days (FIRST EPSS). As of Oct 1, 2026.
EPSS probability 0.23112
Score over time
2022–2026- EPSS v2
- EPSS v3
- EPSS v4
- EPSS v5
Percentile over time
- EPSS v2
- EPSS v3
- EPSS v4
- EPSS v5
Table of values (49 key points)
Flat stretches are collapsed; showing up to 120 newest points.
| Date | Score | Percentile | Model |
|---|---|---|---|
| Oct 1, 2026 | 23.11% (0.23112) | 97.70th | v5 (v2026.06.15) |
| Jun 15, 2026 | 23.11% (0.23112) | 97.47th | v5 (v2026.06.15) |
| Mar 4, 2026 | 56.86% (0.56857) | 98.08th | v4 (v2025.03.14) |
| Mar 1, 2026 | 67.25% (0.67249) | 98.54th | v4 (v2025.03.14) |
| Feb 4, 2026 | 56.86% (0.56857) | 98.06th | v4 (v2025.03.14) |
| Feb 1, 2026 | 67.25% (0.67249) | 98.53th | v4 (v2025.03.14) |
| Jan 4, 2026 | 56.86% (0.56857) | 98.04th | v4 (v2025.03.14) |
| Jan 1, 2026 | 67.25% (0.67249) | 98.51th | v4 (v2025.03.14) |
| Dec 28, 2025 | 56.86% (0.56857) | 98.02th | v4 (v2025.03.14) |
| Dec 27, 2025 | 39.41% (0.39411) | 97.17th | v4 (v2025.03.14) |
| Dec 4, 2025 | 56.86% (0.56857) | 98.01th | v4 (v2025.03.14) |
| Dec 1, 2025 | 67.25% (0.67249) | 98.50th | v4 (v2025.03.14) |
| Nov 4, 2025 | 56.86% (0.56857) | 98.01th | v4 (v2025.03.14) |
| Nov 1, 2025 | 67.25% (0.67249) | 98.50th | v4 (v2025.03.14) |
| Oct 28, 2025 | 56.86% (0.56857) | 98.00th | v4 (v2025.03.14) |
| Oct 27, 2025 | 39.41% (0.39411) | 97.13th | v4 (v2025.03.14) |
| Oct 4, 2025 | 56.86% (0.56857) | 98.06th | v4 (v2025.03.14) |
| Oct 1, 2025 | 67.25% (0.67249) | 98.52th | v4 (v2025.03.14) |
| Jul 30, 2025 | 39.41% (0.39411) | 97.16th | v4 (v2025.03.14) |
| Jul 5, 2025 | 56.86% (0.56857) | 97.99th | v4 (v2025.03.14) |
| Jul 1, 2025 | 67.25% (0.67249) | 98.47th | v4 (v2025.03.14) |
| Jun 5, 2025 | 56.86% (0.56857) | 97.98th | v4 (v2025.03.14) |
| Jun 1, 2025 | 67.25% (0.67249) | 98.45th | v4 (v2025.03.14) |
| May 11, 2025 | 56.86% (0.56857) | 97.97th | v4 (v2025.03.14) |
| May 1, 2025 | 67.25% (0.67249) | 98.45th | v4 (v2025.03.14) |
| Apr 20, 2025 | 56.86% (0.56857) | 97.95th | v4 (v2025.03.14) |
| Apr 19, 2025 | 67.25% (0.67249) | 98.43th | v4 (v2025.03.14) |
| Apr 18, 2025 | 56.86% (0.56857) | 97.95th | v4 (v2025.03.14) |
| Apr 17, 2025 | 67.25% (0.67249) | 98.42th | v4 (v2025.03.14) |
| Apr 14, 2025 | 56.86% (0.56857) | 97.94th | v4 (v2025.03.14) |
| Apr 13, 2025 | 67.25% (0.67249) | 98.45th | v4 (v2025.03.14) |
| Apr 7, 2025 | 56.86% (0.56857) | 97.95th | v4 (v2025.03.14) |
| Apr 5, 2025 | 67.25% (0.67249) | 98.45th | v4 (v2025.03.14) |
| Mar 29, 2025 | 56.86% (0.56857) | 97.29th | v4 (v2025.03.14) |
| Mar 28, 2025 | 67.25% (0.67249) | 98.44th | v4 (v2025.03.14) |
| Mar 17, 2025 | 56.86% (0.56857) | 97.91th | v4 (v2025.03.14) |
| Dec 17, 2024 | 5.74% (0.05741) | 93.25th | v3 (v2023.03.01) |
| Jun 9, 2024 | 3.68% (0.03678) | 91.74th | v3 (v2023.03.01) |
| May 5, 2024 | 3.22% (0.03222) | 91.15th | v3 (v2023.03.01) |
| Mar 2, 2024 | 2.30% (0.02298) | 89.37th | v3 (v2023.03.01) |
| Dec 27, 2023 | 1.99% (0.01994) | 87.58th | v3 (v2023.03.01) |
| Sep 17, 2023 | 2.05% (0.02053) | 87.66th | v3 (v2023.03.01) |
| Aug 11, 2023 | 1.46% (0.01457) | 85.02th | v3 (v2023.03.01) |
| Jul 3, 2023 | 1.05% (0.01055) | 82.02th | v3 (v2023.03.01) |
| Apr 13, 2023 | 0.94% (0.00935) | 80.71th | v3 (v2023.03.01) |
| Mar 7, 2023 | 0.73% (0.00735) | 77.82th | v3 (v2023.03.01) |
| Mar 6, 2023 | 2.69% (0.02686) | 82.85th | v2 (v2022.01.01) |
| Apr 1, 2022 | 2.69% (0.02686) | 81.17th | v2 (v2022.01.01) |
| Feb 4, 2022 | 2.69% (0.02686) | 62.66th | v2 (v2022.01.01) |
Weaknesses (1)
References (20)
- http://lists.opensuse.org/opensuse-security-announce/2016-08/msg00010.html vendor-advisoryx_refsource_SUSE
- http://lists.opensuse.org/opensuse-security-announce/2016-08/msg00040.html vendor-advisoryx_refsource_SUSE
- http://lists.opensuse.org/opensuse-updates/2016-08/msg00069.html vendor-advisoryx_refsource_SUSE
- http://www.debian.org/security/2016/dsa-3625 vendor-advisoryx_refsource_DEBIAN
- http://www.openwall.com/lists/oss-security/2016/05/06/3 mailing-listx_refsource_MLISTThird Party Advisory
- http://www.openwall.com/lists/oss-security/2016/05/06/5 mailing-listx_refsource_MLISTRelease NotesThird Party Advisory
- http://www.oracle.com/technetwork/topics/security/linuxbulletinapr2016-2952096.html x_refsource_CONFIRMThird Party Advisory
- http://www.securitytracker.com/id/1035770 vdb-entryx_refsource_SECTRACKThird Party Advisory
- http://www.squid-cache.org/Advisories/SQUID-2016_9.txt x_refsource_CONFIRMVendor Advisory
- http://www.squid-cache.org/Versions/v3/3.4/changesets/SQUID-2016_9.patch x_refsource_CONFIRM
- http://www.squid-cache.org/Versions/v3/3.5/changesets/SQUID-2016_9.patch x_refsource_CONFIRMPatch
- http://www.ubuntu.com/usn/USN-2995-1 vendor-advisoryx_refsource_UBUNTUThird Party Advisory
- https://access.redhat.com/errata/RHSA-2016:1138 vendor-advisoryx_refsource_REDHAT
- https://access.redhat.com/errata/RHSA-2016:1139 vendor-advisoryx_refsource_REDHAT
- https://access.redhat.com/errata/RHSA-2016:1140 vendor-advisoryx_refsource_REDHAT
- https://access.redhat.com/security/cve/CVE-2016-4556 Vendor Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=1334786 Issue Tracking
- https://nvd.nist.gov/vuln/detail/CVE-2016-4556
- https://security.gentoo.org/glsa/201607-01 vendor-advisoryx_refsource_GENTOO
- https://www.cve.org/CVERecord?id=CVE-2016-4556
Change history (0)
No recorded changes yet.
Sources
CVE.org / MITRE
Status PUBLISHED
Assigner mitre
Published May 10, 2016
Updated Aug 6, 2024
Reserved May 6, 2016
Link CVE-2016-4556
CISA Vulnrichment
Updated n/a