Information disclosure in Varnish Cache
| Risk | Medium |
| Patch available | YES |
| Number of vulnerabilities | 1 |
| CVE-ID | CVE-2019-20637 |
| CWE-ID | CWE-200 |
| 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) Information disclosure
EUVDB-ID: #VU30309
Risk: Medium
CVSSv4.0: 6.6 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/U:Green]
CVE-ID: CVE-2019-20637
CWE-ID:
CWE-200 - Information exposure
Exploit availability: No
DescriptionThe vulnerability allows a remote non-authenticated attacker to gain access to sensitive information.
An issue was discovered in Varnish Cache before 6.0.5 LTS, 6.1.x and 6.2.x before 6.2.2, and 6.3.x before 6.3.1. It does not clear a pointer between the handling of one client request and the next request within the same connection. This sometimes causes information to be disclosed from the connection workspace, such as data structures associated with previous requests within this connection or VCL-related temporary headers.
MitigationInstall update from vendor's website.
Vulnerable software versionsVarnish Cache: 6.0.0 - 6.0.4
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/VSV00004.html#vsv00004
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.
