CVE-2023-4235VulnerabilityPublished 17 Apr 2024Updated 4 Nov 2025

CVE-2023-4235: ofono · Memory Buffer Overflow

Affects ofonoSource CVE Database V5

Not known to be exploited · CVSS 8.1 High.

Data as of 26 Oct 2026, 06:26 UTC

CVSS 3.1 base score

8.1High

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.9% chance of exploitation in 30 days – higher than 60% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

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

Attack Vector: Network
Attack Complexity: High
Privileges Required: None
User Interaction: None
Scope: Unchanged
Confidentiality: High
Integrity: High
Availability: High

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: High: A successful attack depends on conditions beyond the attacker's control. That is, a successful attack cannot be accomplished at will, but requires the attacker to invest in some measurable amount of effort in preparation or execution against the vulnerable component before a successful attack can be expected. For example, a successful attack may require an attacker to: gather knowledge about the environment in which the vulnerable target/component exists; prepare the target environment to improve exploit reliability; or inject themselves into the logical network path between the target and the resource requested by the victim in order to read and/or modify network communications (e.g., a man in the middle attack).
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: High: There is total loss of confidentiality, resulting in all resources within the impacted component being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact.
Integrity: High: There is a total loss of integrity, or a complete loss of protection. For example, the attacker is able to modify any/all files protected by the impacted component. Alternatively, only some files can be modified, but malicious modification would present a direct, serious consequence to the impacted component.
Availability: High: There is total loss of availability, resulting in the attacker being able to fully deny access to resources in the impacted component; this loss is either sustained (while the attacker continues to deliver the attack) or persistent (the condition persists even after the attack has completed). Alternatively, the attacker has the ability to deny some availability, but the loss of availability presents a direct, serious consequence to the impacted component (e.g., the attacker cannot disrupt existing connections, but can prevent new connections; the attacker can repeatedly exploit a vulnerability that, in each instance of a successful attack, leaks a only small amount of memory, but after repeated exploitation causes a service to become completely unavailable).

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 17 Apr 2024
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 2026-10-26.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

AI-suggested

To mitigate CVE-2023-4235, European organizations should: 1) Monitor ofono project repositories and security advisories closely and apply patches or updates as soon as they become available. 2) Restrict access to modem interfaces to trusted personnel and systems only, using strong authentication and network segmentation to limit exposure. 3) Implement SMS filtering and validation at the network level to detect and block malformed or suspicious SMS delivery reports before they reach vulnerable devices. 4) Employ runtime protections such as stack canaries, address space layout randomization (ASLR), and control-flow integrity (CFI) on affected systems to reduce exploitation success. 5) Conduct regular security audits and penetration testing focused on telephony infrastructure to identify and remediate similar vulnerabilities. 6) Consider deploying intrusion detection systems (IDS) capable of monitoring cellular traffic anomalies. 7) For embedded devices, ensure secure firmware update mechanisms are in place to facilitate timely patch deployment. 8) Engage with telecom providers to understand their mitigation strategies and coordinate on threat intelligence sharing.

Description

A flaw was found in ofono, an Open Source Telephony on Linux. A stack overflow bug is triggered within the decode_deliver_report() function during the SMS decoding. It is assumed that the attack scenario is accessible from a compromised modem, a malicious base station, or just SMS. There is a bound check for this memcpy length in decode_submit(), but it was forgotten in decode_deliver_report().

Impact

For European organizations, the impact of CVE-2023-4235 can be substantial, particularly for telecom operators, mobile network infrastructure providers, and enterprises using Linux-based telephony stacks in their communication systems. Exploitation could lead to unauthorized access to sensitive communications, disruption of telephony services, or full system compromise of devices managing mobile broadband connections. This could affect critical infrastructure, including emergency services, corporate communications, and IoT deployments reliant on cellular connectivity. The vulnerability's ability to be triggered remotely via SMS or compromised modems increases the attack surface. Given Europe's advanced telecom infrastructure and increasing adoption of Linux-based embedded systems in telecommunications, the risk of targeted attacks or collateral damage from compromised cellular networks is significant. Additionally, regulatory requirements such as GDPR impose strict obligations on protecting communication confidentiality and integrity, meaning exploitation could result in legal and reputational consequences.

Summary

CVE-2023-4235 is a stack overflow vulnerability identified in the ofono project, an open-source telephony stack used primarily on Linux-based systems to manage mobile broadband and telephony functions. The vulnerability arises in the decode_deliver_report() function, which processes SMS delivery reports. Unlike the decode_submit() function, which properly validates the length parameter before performing a memcpy operation, decode_deliver_report() lacks this boundary check, allowing an attacker to overflow the stack by providing a specially crafted SMS delivery report. This memory corruption can lead to arbitrary code execution, denial of service, or system compromise. The attack vector includes scenarios where an attacker has access to the modem interface, a malicious cellular base station, or can send crafted SMS messages directly to the device. No privileges or user interaction are required, making remote exploitation feasible under certain conditions. The CVSS v3.1 score of 8.1 reflects the network attack vector, high impact on confidentiality, integrity, and availability, and the complexity of attack being high due to the need for specific conditions such as modem access or malicious network infrastructure. No public exploits are known yet, but the vulnerability poses a significant risk to systems relying on ofono for telephony services, especially embedded devices and Linux-based mobile broadband routers or gateways.

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Exploitation evidence

What to do

Description

AI analysisMachine-generated, updated 4 Nov 2025, 18:33 UTC

Technical details

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