CVE-2019-12521 | Date: (C)2020-04-16 (M)2024-02-22 |
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.
CVSS Score and Metrics +CVSS Score and Metrics -CVSS V3 Severity: | CVSS V2 Severity: |
CVSS Score : 5.9 | CVSS Score : 4.3 |
Exploit Score: 2.2 | Exploit Score: 8.6 |
Impact Score: 3.6 | Impact Score: 2.9 |
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CVSS V3 Metrics: | CVSS V2 Metrics: |
Attack Vector: NETWORK | Access Vector: NETWORK |
Attack Complexity: HIGH | Access Complexity: MEDIUM |
Privileges Required: NONE | Authentication: NONE |
User Interaction: NONE | Confidentiality: NONE |
Scope: UNCHANGED | Integrity: NONE |
Confidentiality: NONE | Availability: PARTIAL |
Integrity: NONE | |
Availability: HIGH | |
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