CVE-2021-20733: Improper authorization in handler for custom URL scheme vulnerability in あすけんダイエット (asken diet) for Android ve

Routine

MEDIUM 6.1UPGRADE

CVE-2021-20733 is a medium-severity flaw (CVSS 6.1) affecting asken. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Improper authorization in handler for custom URL scheme vulnerability in あすけんダイエット (asken diet) for Android versions from v.3.0.0 to v.4.2.x allows a remote attacker to lead a user to access an arbitrary website via the vulnerable App.

Why this priority

No elevated risk signals yet

A fixed release or distro patch exists.

Risk facts

CVSS score	6.1 (Medium)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	Required
EPSS exploit chance	0.8% (top 43%)
CISA exploited list	No
Weakness	CWE-862
Published	2021-06-22
Last modified	2026-06-17

Publisher (CNA): JPCERT/CC · Vendor: asken

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

Am I affected?

Timeline

2021-06-22 02:15 UTCPublished CVE record published
2026-06-17 03:34 UTCUpdated Record last modified

asken asken UPGRADE

Affected: >= 3.0.0 and < 4.3.0

Fixed in: 4.3.0

Safe to downgrade to: a release before 3.0.0

1. Check installed version

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

2. UPGRADE to 4.3.0 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade asken

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade asken

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 3.0.0 (Debian / Ubuntu)

apt-cache madison asken sudo apt install asken=<VERSION_BEFORE_3.0.0> sudo apt-mark hold asken

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

dnf --showduplicates list asken sudo dnf downgrade asken-<VERSION_BEFORE_3.0.0> sudo dnf versionlock add asken

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-2021-20733?

asken: upgrade to 4.3.0. Exact commands for each OS are on this page.

Is CVE-2021-20733 being exploited?

CVE-2021-20733 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-2021-20733 affect?

CVE-2021-20733 affects asken. Severity is medium (CVSS 6.1). Improper authorization in handler for custom URL scheme vulnerability in あすけんダイエット (asken diet) for Android versions from v.3.0.0 to v.4.2.x allows a remote attacker to lead a user to access an arbitrary website via the vulnerable App.

How urgent is CVE-2021-20733?

Priority 36/100. No elevated risk signals yet.

Software pages

Android vulnerabilities

References

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