Out-of-bounds Read in Openssl

CVE-2023-1255

Issue summary: The AES-XTS cipher decryption implementation for 64 bit ARM platform contains a bug that could cause it to read past the input buffer, leading to a crash. Impact summary: Applications that use the AES-XTS algorithm on the 64 bit ARM platform can crash in rare circumstances. The AES-XTS algorithm is usually used for disk encryption. The AES-XTS cipher decryption implementation for 64 bit ARM platform will read past the end of the ciphertext buffer if the ciphertext size is 4 mod 5 in 16 byte blocks, e.g. 144 bytes or 1024 bytes. If the memory after the ciphertext buffer is unmapped, this will trigger a crash which results in a denial of service. If an attacker can control the size and location of the ciphertext buffer being decrypted by an application using AES-XTS on 64 bit ARM, the application is affected. This is fairly unlikely making this issue a Low severity one.

Vulnerability class: Buffer Overflow

EPSS: 0.010 (57.7th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 5.9 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H.

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2023-1255?
CVE-2023-1255 is a medium-severity vulnerability in Openssl, classified under Out-of-bounds Read. CVSS score: 5.9/10. Published 2023-04-20.
How severe is CVE-2023-1255?
Medium severity. CVSS v3 base score is 5.9 out of 10.
Is CVE-2023-1255 known to be exploited?
5 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.