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Attack ChainAIDerived

Hypothetical attack flow derived from CVE metadata – not a confirmed exploit chain

  1. Access
    Authenticate as local user
  2. Delivery
    Issue concurrent autofs enum + invalidate requests
  3. Exploit
    Win race between enumeration completion and map invalidation
  4. Execution
    Leak memory on each iteration
  5. Impact
    Exhaust memory and crash autofs service

Vulnerability Assessment

Weakness
CWE
ASVS 5.0
V15 - Secure Coding and Architecture Resource cleanup on lifecycle end
Exploitation Conditions

Requires local, authenticated access to a host where the SSSD autofs responder is active and processing map enumeration - i.e., SSSD configured with the autofs service enabled. The attacker must repeatedly send concurrent map enumeration and map invalidation requests to hit the narrow timing window between asynchronous enumeration completion and map invalidation. Exploitation is limited by several factors: it cannot be performed remotely (AV:L), it requires valid local credentials (PR:L), and it depends on reliably winning a race condition (AC:H), which makes successful, sustained exploitation timing-dependent and non-deterministic. Hosts not running the autofs responder are not exposed. Impact is confined to availability (crash/degradation of the autofs service) with no data exposure or modification.

Impact

This is a low-to-moderate real-world priority despite the enterprise ubiquity of the affected software. The CVSS 3.1 vector (AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H, base 4.7 Medium) signals the practical limits clearly: exploitation is local only (AV:L), requires an already-authenticated local user (PR:L), and depends on winning a timing race condition (AC:H), with impact confined to availability (A:H) - no confidentiality or integrity loss. The sole impact is a memory leak (CWE-772) in the SSSD autofs responder that, if the race is repeatedly won, exhausts memory and crashes or degrades the autofs service. No EPSS score, CISA KEV listing, or public POC was provided, so there is no public exploit identified at time of analysis and no evidence of active exploitation. The combination of local-only access, authenticated prerequisite, high attack complexity, and availability-only impact means this is a genuine but low-urgency DoS bug - not a high-severity remote threat. There is no conflict among the available signals; the main gap is the absence of any exploitation-probability data (EPSS) and patch/fixed-version detail in the provided input.

Exploit ScenarioDerived

An authenticated local user on a RHEL or OpenShift host running SSSD with the autofs responder active writes a loop that repeatedly fires concurrent autofs map enumeration and map-invalidation requests, aiming to hit the race window between asynchronous enumeration completion and invalidation. Each won race leaks memory; sustained over time this drives excessive memory consumption that disrupts or crashes the autofs service. No public exploit code was identified, and success depends on reliably winning a timing-sensitive race (AC:H).

This Month Plan within 30 days. Why: MEDIUM severity (CVSS 4.0-6.9).
No patch listed yet 0.1% exploitation probability (EPSS)

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AnalysisAIv1 – Oct 06, 2026

Local denial of service in the SSSD autofs responder allows an authenticated user on an affected host to exhaust memory by repeatedly racing concurrent map enumeration requests against map invalidation requests. Per the assessed vector (CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H), the attack requires local, valid credentials and depends on winning a narrow timing window, so successful sustained exploitation is non-deterministic; hosts that do not run the autofs responder are not exposed. Impact is confined to availability - leaked memory accumulates until the autofs service is degraded or crashes - with no confidentiality or integrity effect. No public exploit code has been identified and there is no confirmed active exploitation (no CISA KEV listing), and the 4.7 base score reflects the local, high-complexity prerequisites rather than the broad enterprise presence of SSSD.

RemediationAI

No vendor-released patch or fixed SSSD version is identified in the available intelligence; the Red Hat advisory and Bugzilla entry referenced above should be tracked for the errata that carries the upstream fix, and administrators should apply it to the sssd package on RHEL 6 through 10 and on OpenShift Container Platform 4 nodes once it is released. Until then, the most effective compensating control is to stop exposing the vulnerable code path: remove autofs from the SSSD 'services' line in /etc/sssd/sssd.conf (for example, services = nss, pam, ssh, sudo) and restart sssd, which disables the autofs responder entirely - the trade-off is that automount maps served through SSSD will no longer resolve, so this only suits environments using local /etc/auto.* files or another automount source. Reducing the set of local accounts and shell access on hosts that must keep SSSD autofs enabled shrinks the pool of actors who can trigger the race (PR:L means any valid local credential suffices, including service or shared accounts). Because the flaw is a leak rather than a crash primitive, containing its blast radius is practical: add a systemd drop-in for sssd-autofs.service setting MemoryMax=/MemoryHigh= to a value above normal steady-state usage so the responder is restarted before host-wide memory pressure occurs, accepting that hitting the limit forcibly restarts the service and briefly interrupts autofs lookups; alternatively monitor RSS of the sssd-autofs process and schedule periodic restarts of sssd. Disabling enumeration-related options such as 'enumerate = true' reduces the volume of enumeration work that must race against invalidation, lowering (but not eliminating) the probability of hitting the leak. None of these controls fix the underlying CWE-772 lifetime bug, so patching remains the definitive remedy.

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Technical ContextAI · show details

SSSD (System Security Services Daemon) is the identity and authentication broker used across Red Hat Enterprise Linux, providing NSS, PAM, sudo, SSH and autofs services backed by remote directories. The autofs responder (sssd-autofs) resolves automount maps for the automounter and maintains them in its local cache, serving map enumeration asynchronously and invalidating cached maps when the directory reports changes. This flaw is a CWE-772 'Missing Release of Resource after Effective Lifetime' condition: when asynchronous enumeration completion and map invalidation interleave, entries allocated for the enumeration are never released, so each winning race permanently leaks memory. Because enumeration and invalidation are both triggered on behalf of an ordinary local user, the leak can be driven repeatedly, producing unbounded growth in the responder's memory footprint until the process is killed or the host is starved. The supplied CVSS vector (AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H) confirms a local, authenticated, high-complexity path with availability-only impact, and the CPE strings tie the exposure to Red Hat Enterprise Linux 6, 7, 8, 9 and 10 and Red Hat OpenShift Container Platform 4 builds that ship the affected SSSD code path.

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Severity by source

Vendor (redhat) PRIMARY 4.7 MEDIUM
AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H
vuln.today AI 4.7 MEDIUM

Local authenticated user (AV:L/PR:L), success hinges on winning a race so AC:H; only the autofs service is affected (S:U) with availability-only impact (A:H), no C/I.

3.1 AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H
4.0 AV:L/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
Red Hat 4.7 MEDIUM

Primary rating from Vendor (redhat).

CVSS VectorVendor: redhat

Attack Vector
Local
Attack Complexity
High
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

DescriptionCVE.org

A flaw was found in SSSD. A local user can trigger a Denial of Service (DoS) by exploiting a race condition in the autofs responder between asynchronous enumeration completion and map invalidation. By repeatedly sending concurrent map enumeration and invalidation requests, an attacker can cause memory to leak, leading to excessive memory consumption that can disrupt or crash the autofs service.

Threat Intelligence Overview

EPSS Score
0.1%
Top 99% exploitable
Prevalence
High
SSSD ships by default across all supported RHEL releases and OpenShift
Data Quality
5 sources
Confidence: Medium

How this decision was reached

The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.

SignalValue
Severity MEDIUM
CISA KEV No
Public POC No
EPSS 0.1%
Patch available No
Active threat No
Deciding rule
MEDIUM severity (CVSS 4.0-6.9)
What every action level means
Emergency Immediate action required. Criteria: CRITICAL + in CISA KEV (actively exploited) without patch, OR CRITICAL + EPSS > 30% without patch, OR CRITICAL + active threat signals without patch.
Act Now Prioritize within 24-48h. Criteria: in KEV with patch available, OR CRITICAL + public POC, OR HIGH + EPSS > 10%, OR CRITICAL + active threat, OR any CRITICAL severity.
This Week Schedule remediation this week. Criteria: HIGH severity (CVSS 7.0-8.9). Patch within normal change window.
This Month Plan within 30 days. Criteria: MEDIUM severity (CVSS 4.0-6.9), lower exploitation probability. Include in regular patch cycle.
Monitor Track and reassess. Criteria: LOW severity (CVSS 0.1-3.9), minimal exploitation risk. No immediate action needed.

SSVC AssessmentENISA

SSVC Decision· derived
Defer
Exploitation
Poc
System Exposure· derived
Small
Automatable
No
Human Impact· derived
Medium
Technical Impact
Partial

Priority Score

24
Low Medium High Critical
KEV: 0
EPSS: 0
CVSS: +24
PoC: 0
Weaponized: 0
Threat intel: 0
Gov advisory: 0

Attack Technique

Denial of Service attacks render applications or systems unavailable by overwhelming resources or triggering failure conditions.

Affected Products (CPE)CVE.org

cpe:2.3:a:red_hat:red_hat_enterprise_linux_10:*:*:*:*:*:*:*:*
cpe:2.3:a:red_hat:red_hat_enterprise_linux_6:*:*:*:*:*:*:*:*
cpe:2.3:a:red_hat:red_hat_enterprise_linux_7:*:*:*:*:*:*:*:*
cpe:2.3:a:red_hat:red_hat_enterprise_linux_8:*:*:*:*:*:*:*:*
cpe:2.3:a:red_hat:red_hat_enterprise_linux_9:*:*:*:*:*:*:*:*
cpe:2.3:a:red_hat:red_hat_openshift_container_platform_4:*:*:*:*:*:*:*:*
cpe:2.3:a:red_hat:red_hat_openshift_container_platform_4:*:*:*:*:*:*:*:*

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Vendor StatusVendor

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