VulnerabilityPublished 23 Sep 2022Updated 27 May 2025

CVE-2022-38936: PBC · Unchecked Return Value

Source CVE Database V5

Not known to be exploited · CVSS 7.5 High.

Data as of 26 Oct 2026, 13:47 UTC

CVSS 3.1 base score

7.5High

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

EPSS: 0.8% chance of exploitation in 30 days – higher than 58% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

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

Attack Vector: Network
Attack Complexity: Low
Privileges Required: None
User Interaction: None
Scope: Unchanged
Confidentiality: None
Integrity: None
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: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
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: None: There is no loss of confidentiality within the impacted component.
Integrity: None: There is no loss of integrity within 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 23 Sep 2022
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 26 Oct 2026.

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 or the CVSS exploit maturity 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

European organizations should first identify all instances where the PBC library is used within their software stack. Given the absence of an official patch at the time of reporting, organizations should consider the following mitigations: 1) Implement input validation and sanitization on all data fed into the pbc_wmessage_integer function or related Protocol Buffers processing to prevent malformed or malicious inputs that could trigger the segmentation fault. 2) Employ runtime protections such as application-level sandboxing, process isolation, or containerization to limit the impact of potential crashes. 3) Monitor application logs and system metrics for signs of unexpected crashes or restarts related to Protocol Buffers processing. 4) If feasible, update to a patched version of the PBC library once available or apply vendor-provided workarounds. 5) Use network-level protections like rate limiting and intrusion detection systems to detect and block anomalous traffic patterns that could exploit this vulnerability. 6) Engage with software vendors or open-source maintainers to track patch releases and coordinate timely updates. 7) Conduct thorough testing of applications after updates to ensure stability and absence of regressions.

Description

An issue has been found in PBC through 2022-8-27. A SEGV issue detected in the function pbc_wmessage_integer in src/wmessage.c:137.

Impact

For European organizations, the primary impact of CVE-2022-38936 is the potential for denial of service attacks against systems using the PBC library for Protocol Buffers serialization. This could affect backend services, microservices, or any application components that rely on PBC for data exchange. Disruptions could lead to service outages, impacting business operations, customer-facing applications, or internal communications. While there is no direct data breach risk, availability interruptions can cause significant operational and reputational damage, especially in sectors requiring high availability such as finance, healthcare, telecommunications, and critical infrastructure. Organizations using PBC in embedded systems or IoT devices may also face stability issues. Since no authentication or user interaction is required for exploitation, attackers could remotely trigger crashes, increasing the risk of automated or widespread DoS attacks. The lack of known exploits in the wild reduces immediate risk but does not eliminate the threat, as attackers may develop exploits over time.

Summary

CVE-2022-38936 is a high-severity vulnerability identified in the PBC (Protocol Buffers C) library, specifically a segmentation fault (SEGV) issue occurring in the function pbc_wmessage_integer located in src/wmessage.c at line 137. This vulnerability was published on September 23, 2022, and carries a CVSS v3.1 score of 7.5, indicating a high impact. The CVSS vector (AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H) reveals that the vulnerability is remotely exploitable over the network without any privileges or user interaction required. The impact is limited to availability, causing a denial of service (DoS) through application crash due to the segmentation fault. There is no direct impact on confidentiality or integrity. The vulnerability is categorized under CWE-252, which relates to unchecked return values or error conditions, suggesting that the code does not properly handle certain error states leading to the crash. No specific vendor or product information is provided, and no affected versions are listed, which implies that the vulnerability affects the PBC library generally up to the date of discovery. No patches or known exploits in the wild have been reported at the time of publication. The PBC library is used for encoding and decoding Protocol Buffers in C, which is a data serialization format widely used in communication protocols and data storage. Exploitation of this vulnerability could cause applications relying on PBC to crash, potentially disrupting services that depend on these communications or data processing.

CWE-252Unchecked Return Value (opens in a new tab)
Base weaknessLikelihood of exploit: LowOWASP Top 10 A10:2025: Mishandling of Exceptional Conditions (opens in a new tab)
The product does not check the return value from a method or function, which can prevent it from detecting unexpected states and conditions.
Implementation
Check the results of all functions that return a value and verify that the value is expected.
Implementation
For any pointers that could have been modified or provided from a function that can return NULL, check the pointer for NULL before use. When working with a multithreaded or otherwise asynchronous environment, ensure that proper locking APIs are used to lock before the check, and unlock when it has finished.
Implementation
Ensure that you account for all possible return values from the function.
OWASP Cheat Sheets
Logging (opens in a new tab)
Error Handling (opens in a new tab)
OWASP ASVS 4.0.3
V11.1.7 (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

github.com/cloudwu/pbc/issues/158 (opens in a new tab)

Community reviews

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Exploitation evidence

What to do

Description

AI analysisMachine-generated, updated 6 Jul 2025, 04:12 UTC

WeaknessesCWE-252

Technical details

References

Community reviews

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