CVE-2019-12519
Status: ModifiedCritical (9.8)—
An issue was discovered in Squid through 4.7. When handling the tag esi:when when ESI is enabled, Squid calls ESIExpression::Evaluate. This function uses a fixed stack buffer to hold the expression while it's being evaluated. When processing the expression, it could either evaluate the top of the stack, or add a new member to the stack. When adding a new member, there is no check to ensure that the stack won't overflow.
CVSS
- Version: 3.1
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- Base score: 9.8
Exploitation probability (EPSS)
- Probability of exploitation in the next 30 days: 6.72%
- Percentile among all scored CVEs: 94
- Score date: 10/6/2026
EPSS (Exploit Prediction Scoring System, FIRST) estimates how likely a vulnerability is to be exploited in the wild within 30 days. It complements CVSS (impact) and CISA KEV (confirmed exploitation).
Affected technologies (4)
CWEs
- CWE-787
References
- http://lists.opensuse.org/opensuse-security-announce/2020-05/msg00018.html
- http://www.openwall.com/lists/oss-security/2020/04/23/1
- https://gitlab.com/jeriko.one/security/-/blob/master/squid/CVEs/CVE-2019-12519.txt
- https://lists.debian.org/debian-lts-announce/2020/07/msg00009.html
- https://security.gentoo.org/glsa/202005-05
- https://security.netapp.com/advisory/ntap-20210205-0006/
- https://usn.ubuntu.com/4356-1/
- https://www.debian.org/security/2020/dsa-4682
- http://lists.opensuse.org/opensuse-security-announce/2020-05/msg00018.html
- http://www.openwall.com/lists/oss-security/2020/04/23/1
- https://gitlab.com/jeriko.one/security/-/blob/master/squid/CVEs/CVE-2019-12519.txt
- https://lists.debian.org/debian-lts-announce/2020/07/msg00009.html
- https://security.gentoo.org/glsa/202005-05
- https://security.netapp.com/advisory/ntap-20210205-0006/
- https://usn.ubuntu.com/4356-1/
- https://www.debian.org/security/2020/dsa-4682
Raw JSON (NVD)
Show
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"value": "An issue was discovered in Squid through 4.7. When handling the tag esi:when when ESI is enabled, Squid calls ESIExpression::Evaluate. This function uses a fixed stack buffer to hold the expression while it's being evaluated. When processing the expression, it could either evaluate the top of the stack, or add a new member to the stack. When adding a new member, there is no check to ensure that the stack won't overflow."
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"value": "Se detectó un problema en Squid versiones hasta 4.7. Cuando se maneja la etiqueta esi:when cuando ESI está habilitado, Squid llama a la función ESIExpression::Evaluate. Esta función usa un búfer de pila fijado para contener la expresión mientras se está evaluando. Cuando de procesa la expresión, podría evaluar la parte superior de la pila o agregar un nuevo miembro en la pila. Cuando se agrega un nuevo miembro, no se realiza ninguna comprobación para asegurar que la pila no se desborde."
}
],
"lastModified": "2026-06-17T02:14:48.430",
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