Cyber Resilience

CVE-2023-23916

DoS in Splunk Universal Forwarder 8.2.0 – 8.2.12

Public PoCDoS
Published
23 February 2023
Modified
12 March 2025
CVSS Score v3.1 6.5
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
EPSS Score 0.017 75th percentile
Risk Priority 35 floored blend · peak EPSS

Summary

CVE-2023-23916 is a medium-severity Allocation of Resources Without Limits or Throttling (CWE-770) vulnerability in Splunk Universal Forwarder. Its CVSS base score is 6.5 (Medium).

Operationally, ranked in the top 25% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

EU & UK References

Vulnerability Data

An allocation of resources without limits or throttling vulnerability exists in curl <v7.88.0 based on the "chained" HTTP compression algorithms, meaning that a server response can be compressed multiple times and potentially with differentalgorithms. The number of acceptable "links" in…

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this "decompression chain" wascapped, but the cap was implemented on a per-header basis allowing a maliciousserver to insert a virtually unlimited number of compression steps simply byusing many headers. The use of such a decompression chain could result in a "malloc bomb", making curl end up spending enormous amounts of allocated heap memory, or trying to and returning out of memory errors.

CWE(s)

Related Threats

CVEs Like This One

CVE-2023-2828Same product: Debian Debian Linux
CVE-2023-27533Same product: Fedoraproject Fedora
CVE-2023-27535Same product: Debian Debian Linux
CVE-2023-27536Same product: Debian Debian Linux
CVE-2023-27538Same product: Debian Debian Linux
CVE-2023-28321Same product: Debian Debian Linux
CVE-2023-23915Same product: Haxx Curl
CVE-2023-23914Same product: Haxx Curl
CVE-2023-27534Same product: Fedoraproject Fedora
CVE-2023-28322Same product: Fedoraproject Fedora

Affected Assets

haxx
curl
7.57.0 — 7.88.0
fedoraproject
fedora
36
debian
debian linux
10.0, 11.0
netapp
h300s firmware
all versions
netapp
h500s firmware
all versions
netapp
h700s firmware
all versions
netapp
h410s firmware
all versions
netapp
clustered data ontap
all versions
splunk
universal forwarder
9.1.0 · 8.2.0 — 8.2.12 · 9.0.0 — 9.0.6

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)
  • 5 hardening rules · 3 OS baselines
Validate
Prove the fix (OWASP ASVS)
  • V15.4.4

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

addresses: CWE-770

This control implements explicit throttling on session allocation, addressing the weakness of allocating resources without limits.

addresses: CWE-770

Plan testing exercises resource allocation limits and throttling during simulated failures, directly addressing weaknesses that allow unbounded resource use.

addresses: CWE-770

Contingency plan updates ensure recovery strategies address unbounded resource allocation, making it harder for attackers to exploit lack of throttling to cause prolonged outages.

addresses: CWE-770

Provides continuity when unbounded resource allocation at the primary site leads to exhaustion and downtime.

addresses: CWE-770

Alternate services allow operations to continue when primary allocation of resources lacks limits or throttling.

addresses: CWE-770

Explicit planning of security-related actions requires defining limits, windows, and resource allocations, making allocation without throttling far less likely.

addresses: CWE-770

Measures of performance include tracking allocation behavior and throttling effectiveness, reducing the window for resource exhaustion attacks.

addresses: CWE-770

Imposes an inactivity-based limit on network resource allocation, throttling the number of concurrently held connections.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.IR-04 mostly match
degrades

Monitoring capacity and taking action to maintain availability directly reduces unchecked resource allocation.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

detects

Baseline comparison of CPU, memory and bandwidth usage helps surface uncontrolled resource allocations before they cause service degradation.

prevents

Capacity projections and elasticity measures ensure that allocation requests are bounded and can be throttled, reducing the window in which an attacker can force unbounded resource reservations.

mitigates

Defining retention periods and deletion schedules for backup copies prevents indefinite accumulation of data on storage media without corresponding resource-management controls.

mitigates

Architectural redundancy and automatic failover limit the impact of an attacker who forces excessive allocations, because spare capacity can absorb the load until the primary instance recovers.

none

Documented incident response procedures that include activation of continuity plans and controlled recovery help ensure that resource consumption triggered by an incident is bounded and managed rather than left unbounded.

none

Mandating tested continuity procedures that preserve or replace resource-limiting controls prevents an attacker from exploiting the absence of throttling mechanisms during an outage.

References