CVE-2021-38490: Altova MobileTogether Server before 7.3 SP1 allows XML exponential entity expansion, a different vulnerability

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HIGH 7.5REMOTEUPGRADE

CVE-2021-38490 is a high-severity flaw (CVSS 7.5) affecting mobiletogether server. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Altova MobileTogether Server before 7.3 SP1 allows XML exponential entity expansion, a different vulnerability than CVE-2021-37425.

Why this priority

High severity
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	7.5 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	1.0% (top 38%)
CISA exploited list	No
Weakness	CWE-776
Published	2021-08-10
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: altova

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

Am I affected?

Timeline

2021-08-10 22:15 UTCPublished CVE record published
2026-06-17 04:02 UTCUpdated Record last modified

altova mobiletogether server UPGRADE

Affected: >= 7.0 and < 7.3 · 7.3

Fixed in: 7.3

Safe to downgrade to: a release before 7.0

1. Check installed version

apt-cache policy mobiletogether-server || rpm -q mobiletogether-server || mobiletogether-server --version

2. UPGRADE to 7.3 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade mobiletogether-server

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade mobiletogether-server

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

3. If no update is available yet, DOWNGRADE to a release before 7.0 (Debian / Ubuntu)

apt-cache madison mobiletogether-server sudo apt install mobiletogether-server=<VERSION_BEFORE_7.0> sudo apt-mark hold mobiletogether-server

3. If no update is available yet, DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list mobiletogether-server sudo dnf downgrade mobiletogether-server-<VERSION_BEFORE_7.0> sudo dnf versionlock add mobiletogether-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.

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-2021-38490?

mobiletogether server: upgrade to 7.3. Exact commands for each OS are on this page.

Is CVE-2021-38490 being exploited?

CVE-2021-38490 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-2021-38490 affect?

CVE-2021-38490 affects mobiletogether server. Severity is high (CVSS 7.5). Altova MobileTogether Server before 7.3 SP1 allows XML exponential entity expansion, a different vulnerability than CVE-2021-37425.

How urgent is CVE-2021-38490?

Priority 47/100. High severity; Remotely exploitable, no login, no user action

Related CVEs

CVE-2021-37425 CRITICAL 9.1 UPGRADE Altova MobileTogether Server before 7.3 SP1 allows XXE attacks, such as an InfoSetChanges/Changes attack again

References

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