How severe is CVE-2023-1255?

CVE-2023-1255 has a CVSS 3.x base score of 5.9, rated medium severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2023-1255 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (57th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2023-1255?

CVE-2023-1255 affects Openssl. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2023-1255?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2023-1255 published?

CVE-2023-1255 was published on 2023-04-20 and last updated on 2026-06-17.

CVE-2023-1255

CVE-2023-1255 is a medium-severity vulnerability in Openssl with a CVSS 3.x base score of 5.9. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-125.

Key facts

Severity: Medium (CVSS 3.x base score 5.9)
EPSS exploit prediction: 1% (57th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-125
Affected product: Openssl
Published: 2023-04-20
Last modified: 2026-06-17

Description

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.

Frequently asked questions

What is 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.
How severe is CVE-2023-1255?: CVE-2023-1255 has a CVSS 3.x base score of 5.9, rated medium severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2023-1255 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (57th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2023-1255?: CVE-2023-1255 affects Openssl. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2023-1255?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2023-1255 published?: CVE-2023-1255 was published on 2023-04-20 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:openssl:openssl:*:*:*:*:*:*:*:*

More vulnerabilities in Openssl

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Other CWE-125 (Out-of-bounds Read) vulnerabilities

CVE-2026-24826 — Critical (CVSS 10.0): Out-of-bounds Write, Divide By Zero, NULL Pointer Dereference, Use of Uninitialized Resource, Out-of-bounds Read,…
CVE-2024-22004 — Critical (CVSS 10.0): Due to length check, an attacker with privilege access on a Linux Nonsecure operating system can trigger a…
CVE-2021-41556 — Critical (CVSS 10.0): sqclass.cpp in Squirrel through 2.2.5 and 3.x through 3.1 allows an out-of-bounds read (in the core interpreter) that…
CVE-2021-21777 — Critical (CVSS 10.0): An information disclosure vulnerability exists in the Ethernet/IP UDP handler functionality of EIP Stack Group OpENer…
CVE-2017-14451 — Critical (CVSS 10.0): An exploitable out-of-bounds read vulnerability exists in libevm (Ethereum Virtual Machine) of CPP-Ethereum. A…
CVE-2013-0767 — Critical (CVSS 10.0): The nsSVGPathElement::GetPathLengthScale function in Mozilla Firefox before 18.0, Firefox ESR 10.x before 10.0.12 and…

Browse all CWE-125 (Out-of-bounds Read) vulnerabilities →

Threat intelligence

Threat-intel indicators referencing this CVE:

103.90.227.203 (ipv4-addr)
161.97.123.14 (ipv4-addr)
14.161.12.247 (ipv4-addr)
109.236.86.20 (ipv4-addr)