CVE-2021-33635: When malicious images are pulled by isula pull, attackers can execute arbitrary code.

This month

CRITICAL 9.8REMOTEDOWNGRADE

CVE-2021-33635 is a critical-severity flaw (CVSS 9.8) affecting isula. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

When malicious images are pulled by isula pull, attackers can execute arbitrary code.

Why this priority

Critical severity
Remotely exploitable, no login, no user action

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

Risk facts

CVSS score	9.8 (Critical)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.6% (top 54%)
CISA exploited list	No
Weakness	CWE-665, CWE-94
Published	2023-10-29
Last modified	2026-06-17

Publisher (CNA): openEuler · Vendor: openeuler

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

Am I affected?

Timeline

2023-10-29 08:15 UTCPublished CVE record published
2026-06-17 03:54 UTCUpdated Record last modified

openeuler isula DOWNGRADE

Affected: 2.0.8-20210518.144540 · 2.0.18-10 · 2.1.2

Fixed in: no fixed release known

Safe to downgrade to: a release before 2.0.8-20210518.144540

1. Check installed version

apt-cache policy isula || rpm -q isula || isula --version

2. No fixed release: DOWNGRADE to a release before 2.0.8-20210518.144540 (Debian / Ubuntu)

apt-cache madison isula sudo apt install isula=<VERSION_BEFORE_2.0.8-20210518.144540> sudo apt-mark hold isula

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

dnf --showduplicates list isula sudo dnf downgrade isula-<VERSION_BEFORE_2.0.8-20210518.144540> sudo dnf versionlock add isula

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-2021-33635?

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

Is CVE-2021-33635 being exploited?

CVE-2021-33635 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-2021-33635 affect?

CVE-2021-33635 affects isula. Severity is critical (CVSS 9.8). When malicious images are pulled by isula pull, attackers can execute arbitrary code.

How urgent is CVE-2021-33635?

Priority 51/100. Critical severity; Remotely exploitable, no login, no user action

Related CVEs

CVE-2021-33638 HIGH 8.4 DOWNGRADE When the isula cp command is used to copy files from a container to a host machine and the container is contr
CVE-2021-33637 HIGH 8.4 DOWNGRADE When the isula export command is used to export a container to an image and the container is controlled by an
CVE-2021-33636 HIGH 8.4 DOWNGRADE When the isula load command is used to load malicious images, attackers can execute arbitrary code.

References

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