CVE-2021-25903Network attack vector

Remote denial of service via raw pointer dereference

Published Jan 22, 2021 · Updated Aug 3, 2024

A memory-safety flaw in the Rust cache crate through 2021-01-01 allows remote attackers to trigger a service crash via crafted input. The crate dereferences an internally used raw pointer that safe Rust code can modify, violating pointer validity assumptions and causing undefined behavior. Network reachability and unauthenticated access are reflected in the published assessment; the documented consequence is availability loss rather than data disclosure or modification.

CVSS severity7.5
High
EPSS probability1.40%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

A memory-safety flaw in the Rust cache crate through 2021-01-01 allows remote attackers to trigger a service crash via crafted input. The crate dereferences an internally used raw pointer that safe Rust code can modify, violating pointer validity assumptions and causing undefined behavior. Network reachability and unauthenticated access are reflected in the published assessment; the documented consequence is availability loss rather than data disclosure or modification.

The record

CVE
CVE-2021-25903
Published
Jan 22, 2021
Updated
Aug 3, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-476
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jan 22, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

7.5NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
5.0NVDAV:N/AC:L/Au:N/C:N/I:N/A:P

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-476NULL Pointer Dereference

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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