HIGH
squid: denial of service issue in HTTP response processing
Published Apr 7, 2016
7.5
HIGHCVSS 3.0
EPSS 35.27%
Description
Squid 3.x before 3.5.16 and 4.x before 4.0.8 improperly perform bounds checking, which allows remote attackers to cause a denial of service via a crafted HTTP response, related to Vary headers.
Affected products
No data.
OR
- 3.0
- 3.0
- 3.0
- 3.0
- 3.0
- 3.0
- 3.0
- 3.0
- 3.0
- 3.0.stable1
- 3.0.stable2
- 3.0.stable3
- 3.0.stable4
- 3.0.stable5
- 3.0.stable6
- 3.0.stable7
- 3.0.stable8
- 3.0.stable9
- 3.0.stable10
- 3.0.stable11
- 3.0.stable11
- 3.0.stable12
- 3.0.stable13
- 3.0.stable14
- 3.0.stable15
- 3.0.stable16
- 3.0.stable16
- 3.0.stable17
- 3.0.stable18
- 3.0.stable19
- 3.0.stable20
- 3.0.stable21
- 3.0.stable22
- 3.0.stable23
- 3.0.stable24
- 3.0.stable25
- 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
- 3.1.13
- 3.1.14
- 3.1.15
- 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
- 3.3.0.2
- 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
- 3.4.0.1
- 3.4.0.2
- 3.4.0.3
- 3.4.1
- 3.4.2
- 3.4.3
- 3.4.4
- 3.4.8
- 3.4.9
- 3.4.10
- 3.4.11
- 3.4.12
- 3.4.13
- 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
- 4.0.1
- 4.0.2
- 4.0.3
- 4.0.4
- 4.0.5
- 4.0.6
- 4.0.7
No data.
Red Hat Enterprise Linux 7
squid-7:3.5.20-2.el7
Fixed · RHSA-2016:2600
Red Hat Enterprise Linux 5
squid
Not affected
Red Hat Enterprise Linux 6
squid
Will not fix
Red Hat Enterprise Linux 6
squid34
Will not fix
| Product | Package | State | Advisory |
|---|---|---|---|
| Red Hat Enterprise Linux 7 | squid-7:3.5.20-2.el7 | Fixed | RHSA-2016:2600 |
| Red Hat Enterprise Linux 5 | squid | Not affected | n/a |
| Red Hat Enterprise Linux 6 | squid | Will not fix | n/a |
| Red Hat Enterprise Linux 6 | squid34 | Will not fix | n/a |
No package ranges for this CVE.
Remediation
Red Hat statement
Red Hat Product Security has rated this issue as having Moderate security impact. This issue is not currently planned to be addressed in future updates. For additional information, refer to the Issue Severity Classification: https://access.redhat.com/security/updates/classification/.
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.
35.27% 0.35265
Estimated probability of exploitation in the wild in the next 30 days (FIRST EPSS). As of Oct 1, 2026.
EPSS probability 0.35265
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 (56 key points)
Flat stretches are collapsed; showing up to 120 newest points.
| Date | Score | Percentile | Model |
|---|---|---|---|
| Oct 1, 2026 | 35.27% (0.35265) | 98.40th | v5 (v2026.06.15) |
| Aug 23, 2026 | 35.75% (0.35748) | 98.39th | v5 (v2026.06.15) |
| Jun 15, 2026 | 34.46% (0.34461) | 98.20th | v5 (v2026.06.15) |
| Mar 4, 2026 | 69.62% (0.69622) | 98.63th | v4 (v2025.03.14) |
| Mar 1, 2026 | 67.64% (0.67644) | 98.55th | v4 (v2025.03.14) |
| Feb 23, 2026 | 69.62% (0.69622) | 98.62th | v4 (v2025.03.14) |
| Feb 18, 2026 | 70.94% (0.70935) | 98.66th | v4 (v2025.03.14) |
| Feb 4, 2026 | 69.62% (0.69622) | 98.61th | v4 (v2025.03.14) |
| Feb 1, 2026 | 76.21% (0.76209) | 98.89th | v4 (v2025.03.14) |
| Jan 4, 2026 | 69.62% (0.69622) | 98.59th | v4 (v2025.03.14) |
| Jan 1, 2026 | 76.21% (0.76209) | 98.89th | v4 (v2025.03.14) |
| Dec 28, 2025 | 69.62% (0.69622) | 98.59th | v4 (v2025.03.14) |
| Dec 27, 2025 | 50.54% (0.50544) | 97.75th | v4 (v2025.03.14) |
| Dec 17, 2025 | 69.62% (0.69622) | 98.59th | v4 (v2025.03.14) |
| Dec 13, 2025 | 48.69% (0.48689) | 97.63th | v4 (v2025.03.14) |
| Dec 4, 2025 | 50.79% (0.50786) | 97.72th | v4 (v2025.03.14) |
| Dec 1, 2025 | 47.78% (0.47784) | 97.59th | v4 (v2025.03.14) |
| Nov 4, 2025 | 50.79% (0.50786) | 97.71th | v4 (v2025.03.14) |
| Nov 1, 2025 | 47.78% (0.47784) | 97.59th | v4 (v2025.03.14) |
| Oct 28, 2025 | 50.79% (0.50786) | 97.70th | v4 (v2025.03.14) |
| Oct 27, 2025 | 32.72% (0.32720) | 96.67th | v4 (v2025.03.14) |
| Oct 4, 2025 | 50.79% (0.50786) | 97.76th | v4 (v2025.03.14) |
| Oct 1, 2025 | 47.78% (0.47784) | 97.65th | v4 (v2025.03.14) |
| Sep 6, 2025 | 32.72% (0.32720) | 96.73th | v4 (v2025.03.14) |
| Sep 1, 2025 | 27.90% (0.27901) | 96.32th | v4 (v2025.03.14) |
| Aug 20, 2025 | 32.72% (0.32720) | 96.72th | v4 (v2025.03.14) |
| Aug 4, 2025 | 38.22% (0.38224) | 97.09th | v4 (v2025.03.14) |
| Aug 1, 2025 | 33.08% (0.33081) | 96.76th | v4 (v2025.03.14) |
| Jul 30, 2025 | 38.22% (0.38224) | 97.09th | v4 (v2025.03.14) |
| Jul 4, 2025 | 59.75% (0.59748) | 98.14th | v4 (v2025.03.14) |
| Jul 1, 2025 | 56.97% (0.56973) | 98.00th | v4 (v2025.03.14) |
| Jun 19, 2025 | 59.75% (0.59748) | 98.12th | v4 (v2025.03.14) |
| Jun 4, 2025 | 58.26% (0.58259) | 98.05th | v4 (v2025.03.14) |
| Jun 1, 2025 | 51.92% (0.51917) | 97.77th | v4 (v2025.03.14) |
| May 4, 2025 | 58.26% (0.58259) | 98.04th | v4 (v2025.03.14) |
| May 1, 2025 | 51.92% (0.51917) | 97.75th | v4 (v2025.03.14) |
| Apr 20, 2025 | 58.26% (0.58259) | 98.02th | v4 (v2025.03.14) |
| Apr 19, 2025 | 51.92% (0.51917) | 97.72th | v4 (v2025.03.14) |
| Apr 16, 2025 | 58.26% (0.58259) | 98.02th | v4 (v2025.03.14) |
| Apr 13, 2025 | 51.92% (0.51917) | 97.71th | v4 (v2025.03.14) |
| Mar 30, 2025 | 58.26% (0.58259) | 98.01th | v4 (v2025.03.14) |
| Mar 29, 2025 | 69.17% (0.69174) | 98.13th | v4 (v2025.03.14) |
| Mar 26, 2025 | 58.26% (0.58259) | 98.00th | v4 (v2025.03.14) |
| Mar 25, 2025 | 51.92% (0.51917) | 97.69th | v4 (v2025.03.14) |
| Mar 22, 2025 | 58.26% (0.58259) | 98.03th | v4 (v2025.03.14) |
| Mar 21, 2025 | 51.92% (0.51917) | 97.72th | v4 (v2025.03.14) |
| Mar 20, 2025 | 58.26% (0.58259) | 98.03th | v4 (v2025.03.14) |
| Mar 19, 2025 | 51.92% (0.51917) | 97.60th | v4 (v2025.03.14) |
| Mar 17, 2025 | 54.74% (0.54741) | 97.79th | v4 (v2025.03.14) |
| Dec 17, 2024 | 4.84% (0.04842) | 92.64th | v3 (v2023.03.01) |
| Jul 9, 2023 | 5.97% (0.05971) | 92.43th | v3 (v2023.03.01) |
| Apr 20, 2023 | 5.62% (0.05617) | 92.08th | v3 (v2023.03.01) |
| Mar 7, 2023 | 4.83% (0.04825) | 91.45th | v3 (v2023.03.01) |
| Mar 6, 2023 | 1.97% (0.01974) | 78.97th | v2 (v2022.01.01) |
| Apr 1, 2022 | 1.97% (0.01974) | 77.12th | v2 (v2022.01.01) |
| Feb 4, 2022 | 1.97% (0.01974) | 56.20th | v2 (v2022.01.01) |
Weaknesses (2)
References (13)
- 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://rhn.redhat.com/errata/RHSA-2016-2600.html vendor-advisoryx_refsource_REDHAT
- http://www.securitytracker.com/id/1035458 vdb-entryx_refsource_SECTRACK
- http://www.squid-cache.org/Advisories/SQUID-2016_4.txt x_refsource_CONFIRMVendor Advisory
- http://www.squid-cache.org/Versions/v3/3.5/changesets/squid-3.5-14016.patch x_refsource_CONFIRMPatch
- https://access.redhat.com/security/cve/CVE-2016-3948 Vendor Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=1323594 Issue Tracking
- https://nvd.nist.gov/vuln/detail/CVE-2016-3948
- https://security.gentoo.org/glsa/201607-01 vendor-advisoryx_refsource_GENTOO
- https://usn.ubuntu.com/3557-1/ vendor-advisoryx_refsource_UBUNTU
- https://www.cve.org/CVERecord?id=CVE-2016-3948
Change history (0)
No recorded changes yet.
Sources
CVE.org / MITRE
Status PUBLISHED
Assigner mitre
Published Apr 7, 2016
Updated Aug 6, 2024
Reserved Apr 1, 2016
Link CVE-2016-3948
CISA Vulnrichment
Updated n/a