5.9 Medium
CVSS3
Attack Vector
NETWORK
Attack Complexity
HIGH
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
HIGH
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
7.5 High
AI Score
Confidence
High
4.3 Medium
CVSS2
Access Vector
NETWORK
Access Complexity
MEDIUM
Authentication
NONE
Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
PARTIAL
AV:N/AC:M/Au:N/C:N/I:N/A:P
0.03 Low
EPSS
Percentile
90.6%
An issue was discovered in Squid through 4.7. When Squid is parsing ESI, it keeps the ESI elements in ESIContext. ESIContext contains a buffer for holding a stack of ESIElements. When a new ESIElement is parsed, it is added via addStackElement. addStackElement has a check for the number of elements in this buffer, but it’s off by 1, leading to a Heap Overflow of 1 element. The overflow is within the same structure so it can’t affect adjacent memory blocks, and thus just leads to a crash while processing.
CPE | Name | Operator | Version |
---|---|---|---|
ubuntu_linux | eq | 16.04 | |
ubuntu_linux | eq | 18.04 | |
ubuntu_linux | eq | 19.10 | |
ubuntu_linux | eq | 20.04 | |
debian_linux | eq | 9.0 | |
debian_linux | eq | 10.0 | |
leap | eq | 15.1 | |
squid | ge | 3.0 | |
squid | le | 3.5.28 | |
squid | ge | 4.0 |
lists.opensuse.org/opensuse-security-announce/2020-05/msg00018.html
www.openwall.com/lists/oss-security/2020/04/23/1
gitlab.com/jeriko.one/security/-/blob/master/squid/CVEs/CVE-2019-12521.txt
lists.debian.org/debian-lts-announce/2020/07/msg00009.html
security.gentoo.org/glsa/202005-05
security.netapp.com/advisory/ntap-20210205-0006/
usn.ubuntu.com/4356-1/
www.debian.org/security/2020/dsa-4682
5.9 Medium
CVSS3
Attack Vector
NETWORK
Attack Complexity
HIGH
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
HIGH
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
7.5 High
AI Score
Confidence
High
4.3 Medium
CVSS2
Access Vector
NETWORK
Access Complexity
MEDIUM
Authentication
NONE
Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
PARTIAL
AV:N/AC:M/Au:N/C:N/I:N/A:P
0.03 Low
EPSS
Percentile
90.6%