Monitoring::Logs in Zen Load Balancer 3.10.1 allows remote authenticated admins to conduct absolute path traversal attacks, as demonstrated…

published 2020-04-02 6 y ago modified 2026-06-17 4 mo ago also EUVD-2020-3844

cvss: 4.9; version 3.1, NVD
cisa kev: Not listed; not in CISA's catalog
epss: 7.9%; EPSS 7.9% chance of exploitation in 30 days, percentile 94%
public exploits: 1; Metasploit

Monitoring::Logs in Zen Load Balancer 3.10.1 allows remote authenticated admins to conduct absolute path traversal attacks, as demonstrated by a filelog=/etc/shadow request to index.cgi.

Timeline

2020-04-02 Published
2020-04-10 First public exploit (Metasploit auxiliary/scanner/http/zenload_balancer_traversal)

Exploit prediction

7.87% chance of exploitation in the next 30 days, higher than 94% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

Metasploit auxiliary/scanner/http/zenload_balancer_traversal Zen Load Balancer Directory Traversal metasploit auxiliary, normal rank, 2020-04-10
code610.blogspot.com http://code610.blogspot.com/2020/03/pentesting-zen-load-balancer-quick.html referenced PoC, tagged "exploit" by a source, unverified
github.com https://github.com/c610/tmp/blob/master/zenload4patreons.zip referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by	version	score	vector
NVD	3.1	4.9	CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:N/A:N
NVD	2.0	4.0	AV:N/AC:L/Au:S/C:P/I:N/A:N

Classification

Weakness

CWE-22 Improper Limitation of a Pathname to a Restricted Directory

References

code610.blogspot.com /2020/03/pentesting-zen-load-balancer-quick.html
exploit, third-party-advisory
github.com /c610/tmp/blob/master/zenload4patreons.zip
exploit, third-party-advisory

Sources

CVE List CVE-2020-11491
NVD CVE-2020-11491

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary