Buffer overflow in Squid-Cache Squid
CVE-2019-12521
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.
EPSS: 0.058 (92.3th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 5.9 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H.
Affected products
- Squid-cache Squid
- Canonical Ubuntu_linux — versions 16.04, 18.04, 19.10
- Debian Debian_linux — versions 9.0, 10.0
- Opensuse Leap — versions 15.1
- N/a — versions n/a
Weakness classification (CWE)
References
- cve@mitre.org (Third Party Advisory, x_refsource_MISC)
- cve@mitre.org (mailing-list, x_refsource_MLIST, Patch, Mailing List, Third Party Advisory)
- cve@mitre.org (vendor-advisory, Third Party Advisory, x_refsource_DEBIAN)
- cve@mitre.org (vendor-advisory, Mailing List, Third Party Advisory, x_refsource_SUSE)
- cve@mitre.org (vendor-advisory, Third Party Advisory, x_refsource_GENTOO)
- cve@mitre.org (x_refsource_UBUNTU, vendor-advisory, Third Party Advisory)
- cve@mitre.org (mailing-list, x_refsource_MLIST, Mailing List, Third Party Advisory)
- cve@mitre.org (x_refsource_CONFIRM, Third Party Advisory)
Frequently asked questions
- What is CVE-2019-12521?
- CVE-2019-12521 is a medium-severity vulnerability in Squid-Cache Squid, classified under Off-by-one Error. CVSS score: 5.9/10. Published 2020-04-15.
- How severe is CVE-2019-12521?
- Medium severity. CVSS v3 base score is 5.9 out of 10.