CVE-2020-11491: Monitoring::Logs in Zen Load Balancer 3.10.1 allows remote authenticated admins to conduct absolute path trave

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MEDIUM 4.9DOWNGRADE

CVE-2020-11491 is a medium-severity flaw (CVSS 4.9) affecting zen load balancer. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

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.

Why this priority

EPSS top 5%: very likely to be exploited
Public exploit reference

No fix is published yet: follow the downgrade or mitigation steps.

Risk facts

CVSS score	4.9 (Medium)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	High
User interaction	None
EPSS exploit chance	7.9% (top 5%)
CISA exploited list	No
Weakness	CWE-22
Published	2020-04-02
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: zevenet

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2020-04-02 14:15 UTCPublished CVE record published
2026-06-17 02:50 UTCUpdated Record last modified

zevenet zen load balancer DOWNGRADE

Affected: 3.10.1

Fixed in: no fixed release known

Safe to downgrade to: a release before 3.10.1

1. Check installed version

apt-cache policy zen-load-balancer || rpm -q zen-load-balancer || zen-load-balancer --version

2. No fixed release: DOWNGRADE to a release before 3.10.1 (Debian / Ubuntu)

apt-cache madison zen-load-balancer sudo apt install zen-load-balancer=<VERSION_BEFORE_3.10.1> sudo apt-mark hold zen-load-balancer

2. No fixed release: DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list zen-load-balancer sudo dnf downgrade zen-load-balancer-<VERSION_BEFORE_3.10.1> sudo dnf versionlock add zen-load-balancer

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

Public exploits and detection

Public code exists for this CVE. Treat unpatched systems as at risk, and only run PoCs in a lab.

Metasploit: Zen Load Balancer Directory Traversal

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2020-11491?

zen load balancer: downgrade or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2020-11491 being exploited?

CVE-2020-11491 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2020-11491 affect?

CVE-2020-11491 affects zen load balancer. Severity is medium (CVSS 4.9). 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.

How urgent is CVE-2020-11491?

Priority 46/100. EPSS top 5%: very likely to be exploited; Public exploit reference

Related CVEs

CVE-2020-11490 HIGH 7.2 DOWNGRADE Manage::Certificates in Zen Load Balancer 3.10.1 allows remote authenticated admins to execute arbitrary OS co

References

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