CVE-2022-1434Network attack vector

TLS data modification via predictable RC4-MD5 MAC key

Published May 3, 2022 · Updated Sep 17, 2024

Cryptographic integrity failure in OpenSSL 3.0.0 through 3.0.2 allows man-in-the-middle attackers to modify RC4-MD5 TLS data. The rc4_hmac_md5_set_ctx_params function looks up the TLS AAD parameter instead of the supplied MAC-key parameter, making the MAC key predictable. Exploitation requires a non-default weak-cipher build, the legacy provider, security level 0, pre-TLS 1.3, and negotiated RC4-MD5; encrypted data remains confidential.

CVSS severity5.9
Medium
EPSS probability1.06%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Cryptographic integrity failure in OpenSSL 3.0.0 through 3.0.2 allows man-in-the-middle attackers to modify RC4-MD5 TLS data. The rc4_hmac_md5_set_ctx_params function looks up the TLS AAD parameter instead of the supplied MAC-key parameter, making the MAC key predictable. Exploitation requires a non-default weak-cipher build, the legacy provider, security level 0, pre-TLS 1.3, and negotiated RC4-MD5; encrypted data remains confidential.

The record

CVE
CVE-2022-1434
Published
May 3, 2022
Updated
Sep 17, 2024
Vendor
OpenSSL Project
Product
OpenSSL
Classifications
CWE-327, T1557
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 3, 2022CVE publishedPublication date reported by the CVE source.
  2. Sep 17, 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?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=Fixed in OpenSSL 3.0.3 (Affected 3.0.0,3.0.1,3.0.2)

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

OpenSSL Project · OpenSSLversion=Fixed in OpenSSL 3.0.3 (Affected 3.0.0,3.0.1,3.0.2)

Published CVSS scores

5.9NIST NVDCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N
4.3NIST NVDAV:N/AC:M/Au:N/C:N/I:P/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 exploitUnconfirmed

Weakness, pattern, technique

CWE-327Use of a Broken or Risky Cryptographic Algorithm
T1557Adversary-in-the-Middle

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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