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CVE Record

CVE-2025-5449: Libssh: integer overflow in libssh sftp server packet length validation leading to denial of service

A flaw was found in the SFTP server message decoding logic of libssh. The issue occurs due to an incorrect packet length check that allows an integer overflow when handling large payload sizes on 32-bit systems. This issue leads to failed memory allocation and causes the server process to crash, resulting in a denial of service.

MediumCVSS 6.5Not KEV-listedUpdated
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Glexia's TakeAutomated analysismoderate

Security readout for executives and security teams

Plain-English summary

A malformed, oversized SFTP message can crash a vulnerable libssh-based server on 32-bit systems, interrupting file-transfer availability. The reported impact is denial of service, not data theft or modification. An authenticated network user may be able to trigger the failure.

Executive priority

Prioritize affected 32-bit SFTP servers exposed to untrusted authenticated users. Schedule prompt remediation rather than emergency incident response unless crashes or related indicators appear. Confirm Red Hat applicability through installed package metadata because the supplied assessments mark the listed Red Hat products unaffected.

Technical view

CVE-2025-5449 is an integer-overflow flaw in libssh SFTP server packet-length validation. On 32-bit systems, a large payload size can bypass the intended check, cause memory allocation failure, and terminate the server process. CVSS 3.1 is 6.5: network-reachable, low complexity, low privileges, no user interaction, and high availability impact.

Likely exposure

Exposure is most likely where libssh 0.11.0 provides SFTP server functionality on a 32-bit platform. The bundle lists assessed Red Hat Enterprise Linux and OpenShift products as unaffected. Inventory must distinguish libssh from libssh2 and confirm architecture, version, SFTP server use, and vendor backports.

Exploitation context

The CVSS vector indicates network access and low privileges, implying authentication is required. The bundle does not identify public exploitation, and the CVE is not listed as KEV. Treat internet-accessible or broadly accessible SFTP services as more urgent, but do not characterize this as actively exploited.

Researcher notes

The reported weakness is CWE-190 in packet-length handling, with failure occurring during memory allocation on 32-bit systems. Evidence supports process crash and availability loss only; it does not establish confidentiality or integrity impact. The supplied version metadata is somewhat inconsistent because libssh 0.11.0 appears alongside a default unaffected status.

Mitigation direction

  • Review the libssh advisory and vendor guidance for the supported corrected package or backport.
  • Apply vendor-supported updates incorporating the referenced stable-0.11 corrections.
  • Restrict SFTP access to required, trusted users and networks until remediation is confirmed.
  • Use service supervision to restore availability after unexpected crashes while investigating the cause.

Validation and detection

  • Inventory systems embedding libssh and distinguish them from systems using libssh2.
  • Confirm package version, operating-system architecture, and whether libssh SFTP server functionality is enabled.
  • Check vendor security status and package changelogs for CVE-2025-5449 backports.
  • Review SFTP service crash and memory-allocation logs for unexplained failures.
  • Verify patched services remain healthy using approved, non-destructive functional testing.
Prepared
Confidence
medium
Sources
5

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.

ATT&CK lookup starting points

Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.

cwe · low confidence lookup

CWE-190: Exact CWE lookup

Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.

Open ATT&CK lookup
description · low confidence lookup

Container behavior lookup

The affected technology mentions containers, so container-specific ATT&CK technique review may help. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.

Open ATT&CK lookup
cve · low confidence lookup

CVE-2025-5449 mapping review

Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.

Open ATT&CK lookup
Vulnerability profileCVE Program record
Severity
Medium
CVSS
6.5 (3.1)
Known Exploited
No
Published

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

Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

1CVSS vectors
5Timeline events
1ADP providers
9Source links

SSVC decision data

CISA-ADPCISA Coordinator
Timestamp
Version
2.0.3
Exploitation: noneAutomatable: noTechnical Impact: partial

CVSS vector scores

1 official score

We collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.

ScoreVersionSeverityVectorExploitImpactSource
6.5CVSS 3.1MediumCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H2.83.6redhat

Vulnerability scoring details

Base CVSS 3.1 score

6.5Medium
CVSS 3.1 vector shape for CVE-2025-5449Attack VectorAttack ComplexityPrivileges RequiredUser InteractionScopeConfidentiality ImpactIntegrity ImpactAvailability Impact

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

Attack Vector
NetworkAdjacentLocalPhysical
Attack Complexity
LowHigh
Privileges Required
NoneLowHigh
User Interaction
NoneRequired
Scope
ChangedUnchanged
Confidentiality Impact
HighLowNone
Integrity Impact
HighLowNone
Availability Impact
HighLowNone

Vulnerability timeline

Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.

  1. Source timelineredhat

    Reported to Red Hat.

  2. CVE reservedCVE Program

    The CVE ID was reserved by the assigning CNA.

  3. Source timelineredhat

    Made public.

  4. CVE publishedCVE Program

    The CVE record was published.

  5. CVE updatedCVE Program

    The CVE record metadata indicates this as the latest update time.

ADP provider summaries

CISA-ADPCISA ADP Vulnrichment
other:ssvc

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
Unknown vendorlibsshlibssh, 0.11.0unaffected
Red HatRed Hat Enterprise Linux 10libsshunaffected
Red HatRed Hat Enterprise Linux 6libssh2unaffected
Red HatRed Hat Enterprise Linux 7libssh2unaffected
Red HatRed Hat Enterprise Linux 8libsshunaffected
Red HatRed Hat Enterprise Linux 9libsshunaffected
Red HatRed Hat OpenShift Container Platform 4openshift/ose-rhel-coreos-9unaffected
Weakness

CWE details

CWE-190

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.

CWE-190 · source CWE mapping

Integer Overflow or Wraparound

Integer Overflow or Wraparound represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.

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