CVE-2021-45705: An issue was discovered in the nanorand crate before 0.6.1 for Rust

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CRITICAL 9.8REMOTEUPGRADE

CVE-2021-45705 is a critical-severity flaw (CVSS 9.8) affecting nanorand. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

An issue was discovered in the nanorand crate before 0.6.1 for Rust. There can be multiple mutable references to the same object because the TlsWyRand Deref implementation dereferences a raw pointer.

Why this priority

Critical severity
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	9.8 (Critical)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	1.2% (top 31%)
CISA exploited list	No
Published	2021-12-27
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: nanorand project

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

Am I affected?

Timeline

2021-12-27 00:15 UTCPublished CVE record published
2026-06-17 04:13 UTCUpdated Record last modified

nanorand project nanorand UPGRADE

Affected: >= 0.5.0 and < 0.6.1

Fixed in: 0.6.1

Safe to downgrade to: a release before 0.5.0

1. Check installed version

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

2. UPGRADE to 0.6.1 (Debian / Ubuntu)

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

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade nanorand

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 0.5.0 (Debian / Ubuntu)

apt-cache madison nanorand sudo apt install nanorand=<VERSION_BEFORE_0.5.0> sudo apt-mark hold nanorand

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

dnf --showduplicates list nanorand sudo dnf downgrade nanorand-<VERSION_BEFORE_0.5.0> sudo dnf versionlock add nanorand

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-2021-45705?

nanorand: upgrade to 0.6.1. Exact commands for each OS are on this page.

Is CVE-2021-45705 being exploited?

CVE-2021-45705 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-2021-45705 affect?

CVE-2021-45705 affects nanorand. Severity is critical (CVSS 9.8). An issue was discovered in the nanorand crate before 0.6.1 for Rust. There can be multiple mutable references to the same object because the TlsWyRand Deref implementation dereferences a raw pointer.

How urgent is CVE-2021-45705?

Priority 57/100. Critical severity; Remotely exploitable, no login, no user action

Related CVEs

CVE-2020-35926 CRITICAL 9.8 UPGRADE An issue was discovered in the nanorand crate before 0.5.1 for Rust

References

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