CVE-2016-4054
HighBuffer overflow in Squid 3.x before 3.5.17 and 4.x before 4.0.9 allows remote attackers to execute arbitrary code via crafted Edge Side Includes (ESI) responses.
Published Apr 20, 2016 · Updated Jul 8, 2026 · Also known as UBUNTU-CVE-2016-4054
Key Facts
Patch immediately- CVE-2016-4054 is a high-severity vulnerability (CVSS 8.1 v3.1) affecting Squid (Squid-Cache), Ubuntu Linux (Canonical), Linux (Oracle) and 3 more products.
- It is not listed in any known-exploited vulnerabilities catalog. No public exploit code is known.
- EPSS estimates a 78% probability of exploitation in the next 30 days.
- Fixed versions are available, including Squid 3.3.14-20.2, Squid 3.3.14-6.1, Squid 7:3.1.23-16.21.amzn1.
- Brandefense priority: patch immediately, because it is very likely to be exploited soon.
CVSS v3.1
8.1
CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS (30-day exploit likelihood)
78%
Higher than 99.5% of all scored CVEs
Exploited in the wild
No known
Not in a known-exploited catalog
Public exploit code
None known
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Description
Buffer overflow in Squid 3.x before 3.5.17 and 4.x before 4.0.9 allows remote attackers to execute arbitrary code via crafted Edge Side Includes (ESI) responses.
Affected Products
171 affected entries in total| Product | Affected versions | Fixed in |
|---|---|---|
| SquidSquid-Cache | 3.0, 3.1, 3.1.0.1, 3.1.0.10, 3.1.0.11, 3.1.0.12, 3.1.0.13, 3.1.0.14 | 0 |
| Ubuntu LinuxCanonical | 12.04, 14.04, 15.10, 16.04 | n/a |
| LinuxOracle | 6, 7 | n/a |
| squid3debian | See advisory | 3.1.20-2.2+deb7u5 |
| squid34oracle | See advisory | 7:3.4.14-9.el6_8.3 |
Patched Releases
Squid
3.3.14-20.2, 3.3.14-6.1, 7:3.1.23-16.21.amzn1, 7:3.1.23-16.el6_8.4, 7:3.3.8-26.el7_2.3
squid-sysvinit
7:3.3.8-26.el7_2.3
squid3
3.1.20-2.2+deb7u5, 3.1.23-8.16.30.1, 3.3.8-1ubuntu6.8, 3.4.8-6+deb8u3, 3.5.12-1ubuntu7.2
squid34
7:3.4.14-9.el6_8.3
Timeline
Publicly disclosed
Apr 20, 2016
Last updated
Jul 8, 2026
Weakness Type
- CWE-20 Improper Input Validation
- CWE-119 Improper Restriction of Operations within the Bounds of a Memory Buffer
References
- advisoryRHSA-2016:1138
- advisoryRHSA-2016:1139
- advisoryRHSA-2016:1140
- advisoryhttps://bugzilla.suse.com/895773
- advisoryhttps://bugzilla.suse.com/902197
FAQ
Common Questions.
Buffer overflow in Squid 3.x before 3.5.17 and 4.x before 4.0.9 allows remote attackers to execute arbitrary code via crafted Edge Side Includes (ESI) responses.
Affected: Squid (Squid-Cache) versions 3.0, 3.1, 3.1.0.1, 3.1.0.10, 3.1.0.11, 3.1.0.12, 3.1.0.13, 3.1.0.14; Ubuntu Linux (Canonical) versions 12.04, 14.04, 15.10, 16.04; Linux (Oracle) versions 6, 7, among others. The full list is in the CVE brief.
It is not listed in any known-exploited vulnerabilities catalog.
No, it is not currently listed in the CISA Known Exploited Vulnerabilities catalog.
No public exploit code is known.
Fixed versions are available, including Squid 3.3.14-20.2, Squid 3.3.14-6.1, Squid 7:3.1.23-16.21.amzn1.
Brandefense priority: patch immediately, because it is very likely to be exploited soon.
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