Input validation error in Varnish Cache
| Risk | Medium |
| Patch available | YES |
| Number of vulnerabilities | 1 |
| CVE-ID | CVE-2020-11653 |
| CWE-ID | CWE-20 |
| Exploitation vector | Network |
| Public exploit | N/A |
| Vulnerable software |
Varnish Cache Server applications / IDS/IPS systems, Firewalls and proxy servers |
| Vendor | Varnish Software |
Security Bulletin
This security bulletin contains one medium risk vulnerability.
1) Input validation error
EUVDB-ID: #VU30310
Risk: Medium
CVSSv4.0: 6.6 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green]
CVE-ID: CVE-2020-11653
CWE-ID:
CWE-20 - Improper input validation
Exploit availability: No
DescriptionThe vulnerability allows a remote non-authenticated attacker to perform a denial of service (DoS) attack.
An issue was discovered in Varnish Cache before 6.0.6 LTS, 6.1.x and 6.2.x before 6.2.3, and 6.3.x before 6.3.2. It occurs when communication with a TLS termination proxy uses PROXY version 2. There can be an assertion failure and daemon restart, which causes a performance loss.
MitigationInstall update from vendor's website.
Vulnerable software versionsVarnish Cache: 6.0.0 - 6.0.5
CPE2.3 External linkshttps://lists.opensuse.org/opensuse-security-announce/2020-06/msg00026.html
https://lists.opensuse.org/opensuse-security-announce/2020-06/msg00031.html
https://varnish-cache.org/security/VSV00005.html#vsv00005
Q & A
Can this vulnerability be exploited remotely?
Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.
How the attacker can exploit this vulnerability?
The attacker would have to send a specially crafted request to the affected application in order to exploit this vulnerability.
Is there known malware, which exploits this vulnerability?
No. We are not aware of malware exploiting this vulnerability.
