Vulnerability in Squid-Cache Squid
CVE-2019-18678
An issue was discovered in Squid 3.x and 4.x through 4.8. It allows attackers to smuggle HTTP requests through frontend software to a Squid instance that splits the HTTP Request pipeline differently. The resulting Response messages corrupt caches (between a client and Squid) with attacker-controlled content at arbitrary URLs. Effects are isolated to software between the attacker client and Squid. There are no effects on Squid itself, nor on any upstream servers. The issue is related to a request header containing whitespace between a header name and a colon.
Vulnerability class: HTTP Request Smuggling
Published · last modified .
CVSS v3 metric
CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N.
EPSS exploit prediction
EPSS: 0.062 (93.3th percentile), scored .
Low probability of exploitation in the next 30 days, but still tracked. 93rd percentile — 93.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.109 · newest: 0.062 · change: -0.047
Affected products
- Squid-Cache Squid
- Canonical Ubuntu Linux — versions 16.04, 18.04, 19.04
- Debian Linux — versions 8.0
- Fedoraproject Fedora — versions 30, 31
Weakness classification (CWE)
References
- github.com/squid-cache/squid/pull/445 (Patch, Third Party Advisory)
- bugzilla.suse.com/show_bug.cgi (Third Party Advisory, Issue Tracking)
- www.squid-cache.org/Versions/v4/changesets/squid-4-671ba97abe929156dc4c717ee52a… (Release Notes)
- www.squid-cache.org/Advisories/SQUID-2019_10.txt (Third Party Advisory)
- usn.ubuntu.com/4213-1/ (vendor-advisory, Third Party Advisory)
- lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/… (vendor-advisory)
- lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/… (vendor-advisory)
- lists.debian.org/debian-lts-announce/2019/12/msg00011.html (mailing-list, Third Party Advisory)
- security.gentoo.org/glsa/202003-34 (vendor-advisory)
- www.debian.org/security/2020/dsa-4682 (vendor-advisory)
Frequently asked questions
- What is CVE-2019-18678?
- CVE-2019-18678 is a medium-severity vulnerability in Squid-Cache Squid, classified under Inconsistent Interpretation of HTTP Requests (HTTP Request/Response Smuggling). CVSS score: 5.3/10. Published 2019-11-26.
- How severe is CVE-2019-18678?
- Medium severity. CVSS v3 base score is 5.3 out of 10.