Unauthenticated/unencrypted trailing bytes with low-level OCB function calls

MITRE NVD CVE.ORG JSON API Print: PDF PDF

Summary

CVECVE-2025-69418
StatePUBLISHED
Assigneropenssl
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-01-27 16:16:33 UTC
Updated2026-05-12 13:17:24 UTC
DescriptionIssue summary: When using the low-level OCB API directly with AES-NI or<br>other hardware-accelerated code paths, inputs whose length is not a multiple<br>of 16 bytes can leave the final partial block unencrypted and unauthenticated.<br><br>Impact summary: The trailing 1-15 bytes of a message may be exposed in<br>cleartext on encryption and are not covered by the authentication tag,<br>allowing an attacker to read or tamper with those bytes without detection.<br><br>The low-level OCB encrypt and decrypt routines in the hardware-accelerated<br>stream path process full 16-byte blocks but do not advance the input/output<br>pointers. The subsequent tail-handling code then operates on the original<br>base pointers, effectively reprocessing the beginning of the buffer while<br>leaving the actual trailing bytes unprocessed. The authentication checksum<br>also excludes the true tail bytes.<br><br>However, typical OpenSSL consumers using EVP are not affected because the<br>higher-level EVP and provider OCB implementations split inputs so that full<br>blocks and trailing partial blocks are processed in separate calls, avoiding<br>the problematic code path. Additionally, TLS does not use OCB ciphersuites.<br>The vulnerability only affects applications that call the low-level<br>CRYPTO_ocb128_encrypt() or CRYPTO_ocb128_decrypt() functions directly with<br>non-block-aligned lengths in a single call on hardware-accelerated builds.<br>For these reasons the issue was assessed as Low severity.<br><br>The FIPS modules in 3.6, 3.5, 3.4, 3.3, 3.2, 3.1 and 3.0 are not affected<br>by this issue, as OCB mode is not a FIPS-approved algorithm.<br><br>OpenSSL 3.6, 3.5, 3.4, 3.3, 3.0 and 1.1.1 are vulnerable to this issue.<br><br>OpenSSL 1.0.2 is not affected by this issue.

Risk And Classification

Primary CVSS: v3.1 4 MEDIUM from ADP

CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N

Problem Types: CWE-325 | CWE-325 CWE-325 Missing Cryptographic Step

VersionSourceTypeScoreSeverityVector
3.1ADPDECLARED4MEDIUMCVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N
3.1134c704f-9b21-4f2e-91b3-4a467353bcc0Secondary4MEDIUMCVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N

CVSS v3.1 Breakdown

Attack Vector
Local
Attack Complexity
High
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
Low
Integrity
Low
Availability
None

CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N

NVD Known Affected Configurations (CPE 2.3)

TypeVendorProductVersionUpdateEditionLanguage
Application Openssl Openssl All All All All

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA OpenSSL OpenSSL affected 3.6.0 3.6.1 semver Not specified
CNA OpenSSL OpenSSL affected 3.5.0 3.5.5 semver Not specified
CNA OpenSSL OpenSSL affected 3.4.0 3.4.4 semver Not specified
CNA OpenSSL OpenSSL affected 3.3.0 3.3.6 semver Not specified
CNA OpenSSL OpenSSL affected 3.0.0 3.0.19 semver Not specified
CNA OpenSSL OpenSSL affected 1.1.1 1.1.1ze custom Not specified
ADP Siemens SIMATIC S7-1500 TM MFP - GNU/Linux Subsystem affected * custom Not specified

References

ReferenceSourceLinkTags
cert-portal.siemens.com/productcert/html/ssa-265688.html 0b142b55-0307-4c5a-b3c9-f314f3fb7c5e cert-portal.siemens.com
github.com/openssl/openssl/commit/ed40856d7d4ba6cb42779b6770666a65f19cb977 [email protected] github.com Patch
github.com/openssl/openssl/commit/372fc5c77529695b05b4f5b5187691a57ef5dffc [email protected] github.com Patch
openssl-library.org/news/secadv/20260127.txt [email protected] openssl-library.org Vendor Advisory
github.com/openssl/openssl/commit/a7589230356d908c0eca4b969ec4f62106f4f5ae [email protected] github.com Patch
github.com/openssl/openssl/commit/52d23c86a54adab5ee9f80e48b242b52c4cc2347 [email protected] github.com Patch
github.com/openssl/openssl/commit/4016975d4469cd6b94927c607f7c511385f928d8 [email protected] github.com Patch
CVE Program record CVE.ORG www.cve.org canonical
NVD vulnerability detail NVD nvd.nist.gov canonical, analysis

Vendor Comments And Credit

Discovery Credit

CNA: Stanislav Fort (Aisle Research) (en)

CNA: Stanislav Fort (Aisle Research) (en)

© CVE.report 2026 |

Use of this information constitutes acceptance for use in an AS IS condition. There are NO warranties, implied or otherwise, with regard to this information or its use. Any use of this information is at the user's risk. It is the responsibility of user to evaluate the accuracy, completeness or usefulness of any information, opinion, advice or other content. EACH USER WILL BE SOLELY RESPONSIBLE FOR ANY consequences of his or her direct or indirect use of this web site. ALL WARRANTIES OF ANY KIND ARE EXPRESSLY DISCLAIMED. This site will NOT BE LIABLE FOR ANY DIRECT, INDIRECT or any other kind of loss.

CVE, CWE, and OVAL are registred trademarks of The MITRE Corporation and the authoritative source of CVE content is MITRE's CVE web site. This site includes MITRE data granted under the following license.

Free CVE JSON API cve.report/api

CVE.report and Source URL Uptime Status status.cve.report