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.
Published · last modified .
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.
EPSS exploit prediction
EPSS: 0.059 (93.0th percentile), scored .
Low probability of exploitation in the next 30 days, but still tracked. 93rd percentile — 93.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.058 · newest: 0.059 · change: +0.001
Affected products
- Squid-Cache Squid
- Canonical Ubuntu Linux — versions 16.04, 18.04, 19.10
- Debian Linux — versions 9.0, 10.0
- openSUSE Leap — versions 15.1
Weakness classification (CWE)
References
- gitlab.com/jeriko.one/security/-/blob/master/squid/CVEs/CVE-2019-12521.txt (Third Party Advisory)
- www.openwall.com/lists/oss-security/2020/04/23/1 (mailing-list, Patch, Mailing List, Third Party Advisory)
- www.debian.org/security/2020/dsa-4682 (vendor-advisory, Third Party Advisory)
- lists.opensuse.org/opensuse-security-announce/2020-05/msg00018.html (vendor-advisory, Mailing List, Third Party Advisory)
- security.gentoo.org/glsa/202005-05 (vendor-advisory, Third Party Advisory)
- usn.ubuntu.com/4356-1/ (vendor-advisory, Third Party Advisory)
- lists.debian.org/debian-lts-announce/2020/07/msg00009.html (mailing-list, Mailing List, Third Party Advisory)
- security.netapp.com/advisory/ntap-20210205-0006/ (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.