PatchTheCVECVE-2001-1030: Squid before 2.3STABLE5 in HTTP accelerator mode does not enable access control lists (ACLs) when the httpd_ac
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HIGH 7.5WATCHLISTDOWNGRADEDOWNGRADEDOWNGRADE
CVE-2001-1030 is a high-severity flaw (CVSS 7.5) affecting openlinux server, immunix, mandrake single network firewall. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.
Squid before 2.3STABLE5 in HTTP accelerator mode does not enable access control lists (ACLs) when the httpd_accel_host and http_accel_with_proxy off settings are used, which allows attackers to bypass the ACLs and conduct unauthorized activities such as port scanning.
Why this priority
- High severity
- On your watchlist
No fix is published yet: follow the downgrade or mitigation steps.
Risk facts
| CVSS score | 7.5 (High) |
| EPSS exploit chance | 2.0% (top 20%) |
| CISA exploited list | No |
| Published | 2001-07-18 |
| Last modified | 2026-06-16 |
Last updated 2026-06-16 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score
Am I affected?
Timeline
- Published CVE record published
- Updated Record last modified
caldera openlinux server DOWNGRADE
Affected: 3.1
Fixed in: no fixed release known
Safe to downgrade to: a release before 3.1
1. Check installed version
apt-cache policy openlinux-server || rpm -q openlinux-server || openlinux-server --version
2. No fixed release: DOWNGRADE to a release before 3.1 (Debian / Ubuntu)
apt-cache madison openlinux-server
sudo apt install openlinux-server=<VERSION_BEFORE_3.1>
sudo apt-mark hold openlinux-server
2. No fixed release: DOWNGRADE (RHEL / Amazon Linux / Fedora)
dnf --showduplicates list openlinux-server
sudo dnf downgrade openlinux-server-<VERSION_BEFORE_3.1>
sudo dnf versionlock add openlinux-server
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.
immunix immunix DOWNGRADE
Affected: 6.2 · 7.0 · 7.0_beta
Fixed in: no fixed release known
Safe to downgrade to: a release before 6.2
1. Check installed version
apt-cache policy immunix || rpm -q immunix || immunix --version
2. No fixed release: DOWNGRADE to a release before 6.2 (Debian / Ubuntu)
apt-cache madison immunix
sudo apt install immunix=<VERSION_BEFORE_6.2>
sudo apt-mark hold immunix
2. No fixed release: DOWNGRADE (RHEL / Amazon Linux / Fedora)
dnf --showduplicates list immunix
sudo dnf downgrade immunix-<VERSION_BEFORE_6.2>
sudo dnf versionlock add immunix
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.
mandrakesoft mandrake single network firewall DOWNGRADE
Affected: 7.2
Fixed in: no fixed release known
Safe to downgrade to: a release before 7.2
1. Check installed version
apt-cache policy mandrake-single-network-firewall || rpm -q mandrake-single-network-firewall || mandrake-single-network-firewall --version
2. No fixed release: DOWNGRADE to a release before 7.2 (Debian / Ubuntu)
apt-cache madison mandrake-single-network-firewall
sudo apt install mandrake-single-network-firewall=<VERSION_BEFORE_7.2>
sudo apt-mark hold mandrake-single-network-firewall
2. No fixed release: DOWNGRADE (RHEL / Amazon Linux / Fedora)
dnf --showduplicates list mandrake-single-network-firewall
sudo dnf downgrade mandrake-single-network-firewall-<VERSION_BEFORE_7.2>
sudo dnf versionlock add mandrake-single-network-firewall
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.
squid squid web proxy DOWNGRADE
Affected: 2.3stable3 · 2.3stable4
Fixed in: no fixed release known
Safe to downgrade to: a release before 2.3stable3
1. Check installed version
apt-cache policy squid-web-proxy || rpm -q squid-web-proxy || squid-web-proxy --version
2. No fixed release: DOWNGRADE to a release before 2.3stable3 (Debian / Ubuntu)
apt-cache madison squid-web-proxy
sudo apt install squid-web-proxy=<VERSION_BEFORE_2.3stable3>
sudo apt-mark hold squid-web-proxy
2. No fixed release: DOWNGRADE (RHEL / Amazon Linux / Fedora)
dnf --showduplicates list squid-web-proxy
sudo dnf downgrade squid-web-proxy-<VERSION_BEFORE_2.3stable3>
sudo dnf versionlock add squid-web-proxy
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.
mandrakesoft mandrake linux MITIGATE
Affected: 7.1 · 7.2 · 8.0
Fixed in: no fixed release known
Safe to downgrade to: a release before 7.1
Check your OS release
cat /etc/os-release; uname -r
Debian / Ubuntu
sudo apt update && sudo apt full-upgrade
RHEL / Amazon Linux / Fedora
sudo dnf upgrade --refresh
Windows
Install the latest cumulative update from Windows Update
If no patch exists yet
OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.
mandrakesoft mandrake linux corporate server MITIGATE
Affected: 1.0.1
Fixed in: no fixed release known
Safe to downgrade to: a release before 1.0.1
Check your OS release
cat /etc/os-release; uname -r
Debian / Ubuntu
sudo apt update && sudo apt full-upgrade
RHEL / Amazon Linux / Fedora
sudo dnf upgrade --refresh
Windows
Install the latest cumulative update from Windows Update
If no patch exists yet
OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.
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.
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-2001-1030?
openlinux server: downgrade or apply the listed mitigation; immunix: downgrade or apply the listed mitigation; mandrake single network firewall: downgrade or apply the listed mitigation. Exact commands for each OS are on this page.
Is CVE-2001-1030 being exploited?
CVE-2001-1030 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-2001-1030 affect?
CVE-2001-1030 affects openlinux server, immunix, mandrake single network firewall. Severity is high (CVSS 7.5). Squid before 2.3STABLE5 in HTTP accelerator mode does not enable access control lists (ACLs) when the httpd_accel_host and http_accel_with_proxy off settings are used, which allows attackers to bypass the ACLs and conduct unauthorized activ
How urgent is CVE-2001-1030?
Priority 51/100. High severity; On your watchlist
Software pages
Apache HTTP Server vulnerabilities · Squid vulnerabilities
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