CVE-2021-27211Public exploitNetwork attack vector

Hidden-data detection via brute-forced 32-bit seed

Published Feb 15, 2021 · Updated Aug 3, 2024

Weak PRNG seeding in steghide 0.5.1 allows attackers to detect hidden data in image or audio files via offline seed brute force. Steghide XORs four 32-bit chunks of an MD5 password hash into one seed, limiting position generation to 2^32 possibilities and exposing recognizable metadata as a validation oracle. Access to a steghide-produced carrier file is required; seed recovery reveals embedded metadata and, when encryption was disabled, plaintext content.

CVSS severity7.5
High
EPSS probability3.25%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Weak PRNG seeding in steghide 0.5.1 allows attackers to detect hidden data in image or audio files via offline seed brute force. Steghide XORs four 32-bit chunks of an MD5 password hash into one seed, limiting position generation to 2^32 possibilities and exposing recognizable metadata as a validation oracle. Access to a steghide-produced carrier file is required; seed recovery reveals embedded metadata and, when encryption was disabled, plaintext content.

The record

CVE
CVE-2021-27211
Published
Feb 15, 2021
Updated
Aug 3, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-335, T1140
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Feb 15, 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

7.5NIST National Vulnerability DatabaseCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
5.0NIST National Vulnerability DatabaseAV:N/AC:L/Au:N/C:P/I:N/A:N

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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-335Incorrect Usage of Seeds in Pseudo-Random Number Generator (PRNG)
T1140Deobfuscate/Decode Files or Information

Public exploit references

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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