CVE-2024-31879: IBM i RCE Vulnerability

CVE-2024-31879 Overview

CVE-2024-31879 affects IBM i versions 7.2, 7.3, and 7.4. The vulnerability stems from deserialization of untrusted data [CWE-502]. A remote attacker can exploit this flaw to execute arbitrary code, which can result in a denial of service of network ports on the affected system. IBM tracks this issue under X-Force ID 287539.

The vulnerability requires no authentication and no user interaction. Attackers reach the flaw across the network, making exposed IBM i instances directly accessible to exploitation attempts.

Critical Impact
Remote, unauthenticated attackers can trigger arbitrary code paths through unsafe deserialization, disabling network ports and disrupting service availability on IBM i systems.

Affected Products

IBM i 7.2
IBM i 7.3
IBM i 7.4

Discovery Timeline

2024-05-18 - CVE-2024-31879 published to NVD
2025-07-03 - Last updated in NVD database

Technical Details for CVE-2024-31879

Vulnerability Analysis

The issue is an insecure deserialization weakness classified under [CWE-502]. IBM i components accept serialized objects from network sources without validating the type or contents of the incoming stream. When the runtime reconstructs these objects, attacker-controlled data influences object instantiation and method invocation paths.

The EPSS score of 0.755% places this CVE in the 73rd percentile for exploitation probability. While no public exploit code is currently tracked, the network-reachable attack surface increases the operational risk for internet-exposed IBM i hosts.

The primary documented impact is denial of service against network ports. The vulnerability allows arbitrary code execution paths during object reconstruction, which the runtime resolves into resource disruption affecting listening services.

Root Cause

The root cause is the absence of strict type filtering and integrity controls during deserialization. IBM i services accept serialized payloads and instantiate classes without enforcing an allow-list of safe types. This pattern lets attacker-supplied gadget chains execute during object reconstruction, a well-known anti-pattern for Java and similar runtimes.

Attack Vector

The attack vector is network-based with low complexity. An attacker sends a crafted serialized object to a vulnerable IBM i network service. The receiving component deserializes the payload, triggering code execution that disables network ports and produces a denial of service condition. No credentials or user interaction are required.

No verified public proof-of-concept code is available. Refer to the IBM X-Force Vulnerability #287539 entry for additional technical context.

Detection Methods for CVE-2024-31879

Indicators of Compromise

Unexpected termination or unresponsiveness of IBM i network listeners and TCP/IP ports.
Inbound traffic to IBM i services containing Java serialization magic bytes (ac ed 00 05) from untrusted sources.
Abnormal process activity or job failures correlated with crafted network requests on IBM i hosts.

Detection Strategies

Inspect network traffic to IBM i services for serialized object signatures originating outside trusted management networks.
Correlate IBM i system operator messages (QSYSOPR) reporting subsystem or port failures with concurrent inbound network events.
Monitor IBM i audit journal (QAUDJRN) entries for unexpected job initiations or authority failures tied to network services.

Monitoring Recommendations

Forward IBM i audit journals and TCP/IP status events to a centralized logging platform for anomaly review.
Alert on repeated port restarts, subsystem ending events, or TCP/IP stack errors on IBM i partitions.
Track external scanning activity against IBM i management and host server ports (449, 8470-8476).

How to Mitigate CVE-2024-31879

Immediate Actions Required

Apply the IBM security update referenced in the IBM Security Patch Advisory for IBM i 7.2, 7.3, and 7.4.
Restrict network access to IBM i host server ports so only trusted administrative networks can reach them.
Inventory exposed IBM i partitions and confirm release and PTF levels against the IBM advisory.

Patch Information

IBM has released fixes addressed in the official advisory. Review the IBM Security Patch Advisory for the corresponding PTF (Program Temporary Fix) identifiers covering IBM i 7.2, 7.3, and 7.4. Apply the PTFs through standard IBM i service program update procedures and verify installation with the DSPPTF command.

Workarounds

Place IBM i systems behind network segmentation and firewall rules that block untrusted inbound traffic to host server and database ports.
Disable IBM i network services that are not required for production workloads to reduce the exposed deserialization surface.
Require VPN or jump-host access for administrative connectivity to IBM i partitions until PTFs are applied.

bash

# Display installed PTFs to verify patch status on IBM i
DSPPTF LICPGM(5770SS1)

# Restrict TCP/IP host server access to trusted subnets via exit programs
WRKREGINF EXITPNT(QIBM_QZDA_INIT)