CVE-2000-0970: IIS 4.0 and 5.0 .ASP pages send the same Session ID cookie for secure and insecure web sessions, which could a

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HIGH 7.5WATCHLISTDOWNGRADEDOWNGRADE

CVE-2000-0970 is a high-severity flaw (CVSS 7.5) affecting internet information server, internet information services. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

IIS 4.0 and 5.0 .ASP pages send the same Session ID cookie for secure and insecure web sessions, which could allow remote attackers to hijack the secure web session of the user if that user moves to an insecure session, aka the "Session ID Cookie Marking" vulnerability.

Why this priority

High severity
EPSS top 1%: very likely to be exploited
On your watchlist

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

Risk facts

CVSS score	7.5 (High)
EPSS exploit chance	45.7% (top 1%)
CISA exploited list	No
Published	2000-12-19
Last modified	2026-09-23

Publisher (CNA): MITRE · Vendor: microsoft

Last updated 2026-09-23 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2000-12-19 05:00 UTCPublished CVE record published
2026-09-23 10:10 UTCUpdated Record last modified

microsoft internet information server DOWNGRADE

Affected: 4.0

Fixed in: no fixed release known

Safe to downgrade to: a release before 4.0

1. Check installed version

apt-cache policy internet-information-server || rpm -q internet-information-server || internet-information-server --version

2. No fixed release: DOWNGRADE to a release before 4.0 (Debian / Ubuntu)

apt-cache madison internet-information-server sudo apt install internet-information-server=<VERSION_BEFORE_4.0> sudo apt-mark hold internet-information-server

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

dnf --showduplicates list internet-information-server sudo dnf downgrade internet-information-server-<VERSION_BEFORE_4.0> sudo dnf versionlock add internet-information-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.

microsoft internet information services DOWNGRADE

Affected: 5.0

Fixed in: no fixed release known

Safe to downgrade to: a release before 5.0

1. Check installed version

apt-cache policy internet-information-services || rpm -q internet-information-services || internet-information-services --version

2. No fixed release: DOWNGRADE to a release before 5.0 (Debian / Ubuntu)

apt-cache madison internet-information-services sudo apt install internet-information-services=<VERSION_BEFORE_5.0> sudo apt-mark hold internet-information-services

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

dnf --showduplicates list internet-information-services sudo dnf downgrade internet-information-services-<VERSION_BEFORE_5.0> sudo dnf versionlock add internet-information-services

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.

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-2000-0970?

internet information server: downgrade or apply the listed mitigation; internet information services: downgrade or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2000-0970 being exploited?

CVE-2000-0970 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-2000-0970 affect?

CVE-2000-0970 affects internet information server, internet information services. Severity is high (CVSS 7.5). IIS 4.0 and 5.0 .ASP pages send the same Session ID cookie for secure and insecure web sessions, which could allow remote attackers to hijack the secure web session of the user if that user moves to an insecure session, aka the "Session ID

How urgent is CVE-2000-0970?

Priority 56/100. High severity; EPSS top 1%: very likely to be exploited; On your watchlist

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References

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