CVE DATABASE / CVE-2020-15811
CVE-2020-15811
Summary
An issue was discovered in Squid before 4.13 and 5.x before 5.0.4. Due to incorrect data validation, HTTP Request Splitting attacks may succeed against HTTP and HTTPS traffic. This leads to cache poisoning. This allows any client, including browser scripts, to bypass local security and poison the browser cache and any downstream caches with content from an arbitrary source. Squid uses a string search instead of parsing the Transfer-Encoding header to find chunked encoding. This allows an attacker to hide a second request inside Transfer-Encoding: it is interpreted by Squid as chunked and split out into a second request delivered upstream. Squid will then deliver two distinct responses to the client, corrupting any downstream caches.
CVSS 3.1 breakdown
| Base score | 6.5 (MEDIUM) |
| Vector | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N |
| Attack vector | NETWORK |
| Attack complexity | LOW |
| Privileges required | LOW |
| User interaction | NONE |
| Scope | UNCHANGED |
| Confidentiality | NONE |
| Integrity | HIGH |
| Availability | NONE |
Weakness type (CWE)
Affected products
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References
- http://lists.opensuse.org/opensuse-security-announce/2020-09/msg00012.html
- http://lists.opensuse.org/opensuse-security-announce/2020-09/msg00017.html
- https://github.com/squid-cache/squid/security/advisories/GHSA-c7p8-xqhm-49wv
- https://lists.debian.org/debian-lts-announce/2020/10/msg00005.html
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/BE6FKUN7IGTIR2MEEMWYDT7N5EJJLZI2/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/BMTFLVB7GLRF2CKGFPZ4G4R5DIIPHWI3/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/HJJDI7JQFGQLVNCKMVY64LAFMKERAOK7/
- https://security.netapp.com/advisory/ntap-20210219-0007/
- https://security.netapp.com/advisory/ntap-20210226-0006/
- https://security.netapp.com/advisory/ntap-20210226-0007/
- https://usn.ubuntu.com/4477-1/
- https://usn.ubuntu.com/4551-1/
- https://www.debian.org/security/2020/dsa-4751
Data: NIST NVD. NVD last modified 2024-11-21. Always verify against the vendor advisory before acting.