CVE-2019-12521
4.3 Medium
CVSS2
Attack Vector
NETWORK
Attack 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
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
7.7 High
AI Score
Confidence
High
0.034 Low
EPSS
Percentile
91.4%
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.
Affected configurations
References
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
Related
4.3 Medium
CVSS2
Attack Vector
NETWORK
Attack 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
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
7.7 High
AI Score
Confidence
High
0.034 Low
EPSS
Percentile
91.4%