CVE-2023-5363
Incorrect cipher key & IV length processing
Basic Information
- CVE State
- PUBLISHED
- Reserved Date
- October 03, 2023
- Published Date
- October 24, 2023
- Last Updated
- October 14, 2024
- Vendor
- OpenSSL
- Product
- OpenSSL
- Description
- Issue summary: A bug has been identified in the processing of key and initialisation vector (IV) lengths. This can lead to potential truncation or overruns during the initialisation of some symmetric ciphers. Impact summary: A truncation in the IV can result in non-uniqueness, which could result in loss of confidentiality for some cipher modes. When calling EVP_EncryptInit_ex2(), EVP_DecryptInit_ex2() or EVP_CipherInit_ex2() the provided OSSL_PARAM array is processed after the key and IV have been established. Any alterations to the key length, via the "keylen" parameter or the IV length, via the "ivlen" parameter, within the OSSL_PARAM array will not take effect as intended, potentially causing truncation or overreading of these values. The following ciphers and cipher modes are impacted: RC2, RC4, RC5, CCM, GCM and OCB. For the CCM, GCM and OCB cipher modes, truncation of the IV can result in loss of confidentiality. For example, when following NIST's SP 800-38D section 8.2.1 guidance for constructing a deterministic IV for AES in GCM mode, truncation of the counter portion could lead to IV reuse. Both truncations and overruns of the key and overruns of the IV will produce incorrect results and could, in some cases, trigger a memory exception. However, these issues are not currently assessed as security critical. Changing the key and/or IV lengths is not considered to be a common operation and the vulnerable API was recently introduced. Furthermore it is likely that application developers will have spotted this problem during testing since decryption would fail unless both peers in the communication were similarly vulnerable. For these reasons we expect the probability of an application being vulnerable to this to be quite low. However if an application is vulnerable then this issue is considered very serious. For these reasons we have assessed this issue as Moderate severity overall. The OpenSSL SSL/TLS implementation is not affected by this issue. The OpenSSL 3.0 and 3.1 FIPS providers are not affected by this because the issue lies outside of the FIPS provider boundary. OpenSSL 3.1 and 3.0 are vulnerable to this issue.
CVSS Scores
CVSS v3.1
7.5 - HIGH
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
EPSS Score
- Score
- 2.00% (Percentile: 82.78%) as of 2025-06-12
Exploit Status
- Exploited in the Wild
- Yes (2025-06-12 16:31:20 UTC) Source
References
Recent Mentions
Siemens SIMATIC S7-1500 CPU Family
Source: All CISA Advisories • Published: 2025-06-12 12:00:00 UTC
As of January 10, 2023, CISA will no longer be updating ICS security advisories for Siemens product vulnerabilities beyond the initial advisory. For the most up-to-date information on vulnerabilities in this advisory, please see Siemens' ProductCERT Security Advisories (CERT Services | Services | Siemens Global).
View CSAF
1. EXECUTIVE SUMMARY
CVSS v4 8.7
ATTENTION: Exploitable remotely/low attack complexity
Vendor: Siemens
Equipment: SIMATIC S7-1500 CPU family
Vulnerabilities: Missing Encryption of Sensitive Data, Out-of-bounds Read, Use After Free, Stack-based Buffer Overflow, Incorrect Provision of Specified Functionality, Out-of-bounds Write, Incorrect Calculation of Buffer Size, Heap-based Buffer Overflow, External Control of File Name or Path, Uncontrolled Resource Consumption, Improper Input Validation, Truncation of Security-relevant Information, Missing Critical Step in Authentication, Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection'), Access of Resource Using Incompatible Type ('Type Confusion'), Signal Handler Race Condition, Inefficient Algorithmic Complexity, Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition'), NULL Pointer Dereference, Reachable Assertion, Return of Pointer Value Outside of Expected Range, Improper Handling of Length Parameter Inconsistency, Integer Overflow or Wraparound, Improper Locking, Improper Validation of Array Index, Buffer Underwrite ('Buffer Underflow'), Use of Uninitialized Resource, Detection of Error Condition Without Action, Premature Release of Resource During Expected Lifetime
2. RISK EVALUATION
Successful exploitation of these vulnerabilities could allow an attacker to affect the confidentiality, integrity, or availability of affected devices.
3. TECHNICAL DETAILS
3.1 AFFECTED PRODUCTS
Siemens reports that the following products are affected:
SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AB0): V3.1.5 and...
Timeline
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CVE ID Reserved
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CVE Published to Public