Highly exploitable, CVE-2023-4807 poses a critical security risk that could lead to severe breaches.
Status: Modified
Last updated: 🕣 21 Nov 2024, 08:36 UTC
Originally published on: 🕛 08 Sep 2023, 12:15 UTC
Time between publication and last update: 439 days
CVSS Release: version 3
nvd@nist.gov
Primary
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CVE-2023-4807: Issue summary: The POLY1305 MAC (message authentication code) implementation contains a bug that might corrupt the internal state of applications on the Windows 64 platform when running on newer X86_64 processors supporting the AVX512-IFMA instructions. Impact summary: If in an application that uses the OpenSSL library an attacker can influence whether the POLY1305 MAC algorithm is used, the application state might be corrupted with various application dependent consequences. The POLY1305 MAC (message authentication code) implementation in OpenSSL does not save the contents of non-volatile XMM registers on Windows 64 platform when calculating the MAC of data larger than 64 bytes. Before returning to the caller all the XMM registers are set to zero rather than restoring their previous content. The vulnerable code is used only on newer x86_64 processors supporting the AVX512-IFMA instructions. The consequences of this kind of internal application state corruption can be various - from no consequences, if the calling application does not depend on the contents of non-volatile XMM registers at all, to the worst consequences, where the attacker could get complete control of the application process. However given the contents of the registers are just zeroized so the attacker cannot put arbitrary values inside, the most likely consequence, if any, would be an incorrect result of some application dependent calculations or a crash leading to a denial of service. The POLY1305 MAC algorithm is most frequently used as part of the CHACHA20-POLY1305 AEAD (authenticated encryption with associated data) algorithm. The most common usage of this AEAD cipher is with TLS protocol versions 1.2 and 1.3 and a malicious client can influence whether this AEAD cipher is used by the server. This implies that server applications using OpenSSL can be potentially impacted. However we are currently not aware of any concrete application that would be affected by this issue therefore we consider this a Low severity security issue. As a workaround the AVX512-IFMA instructions support can be disabled at runtime by setting the environment variable OPENSSL_ia32cap: OPENSSL_ia32cap=:~0x200000 The FIPS provider is not affected by this issue.
The exploitability of CVE-2023-4807 depends on two key factors: attack complexity (the level of effort required to execute an exploit) and privileges required (the access level an attacker needs).
CVE-2023-4807 presents an accessible attack vector with minimal effort required. Restricting access controls and implementing security updates are critical to reducing exploitation risks.
A lower complexity and fewer privilege requirements make exploitation easier. Security teams should evaluate these aspects to determine the urgency of mitigation strategies, such as patch management and access control policies.
Attack Complexity (AC) measures the difficulty in executing an exploit. A high AC means that specific conditions must be met, making an attack more challenging, while a low AC means the vulnerability can be exploited with minimal effort.
Privileges Required (PR) determine the level of system access necessary for an attack. Vulnerabilities requiring no privileges are more accessible to attackers, whereas high privilege requirements limit exploitation to authorized users with elevated access.
Above is the CVSS Sub-score Breakdown for CVE-2023-4807, illustrating how Base, Impact, and Exploitability factors combine to form the overall severity rating. A higher sub-score typically indicates a more severe or easier-to-exploit vulnerability.
Below is the Impact Analysis for CVE-2023-4807, showing how Confidentiality, Integrity, and Availability might be affected if the vulnerability is exploited. Higher values usually signal greater potential damage.
The EPSS score estimates the probability that this vulnerability will be exploited in the near future.
EPSS Score: 0.043% (probability of exploit)
EPSS Percentile: 12.27%
(lower percentile = lower relative risk)
This vulnerability is less risky than approximately 87.73% of others.
NVD-CWE-noinfo
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