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S5300 FirmwareOperating system · Huawei

CVE-2016-6518

HIGH · 7.5 CVSS v3.0 Published 2016-09-26
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
84/100
Remediation priority · High
Remotely reachable No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
Memory leak in Huawei S9300, S5300, S5700, S6700, S7700, S9700, and S12700 devices allows remote attackers to cause a denial of service (memory consumption and restart) via a large number of malformed packets.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · moderate confidence

Multiple Huawei switch models (S9300, S5300, S5700, S6700, S7700, S9700, S12700) contain a memory leak vulnerability in packet processing logic. Remote attackers can trigger the leak by sending a large volume of malformed packets, causing memory exhaustion that leads to device restart and denial of service.

MitigationApply Huawei firmware patches for affected models. As an interim control, implement traffic filtering or rate limiting at network edges to block malformed packets before they reach affected devices.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
S5300 FirmwareOperating system
Affected:= v200r001c00= v200r002c00= v200r003c00= v200r005c00= v200r005c01= v200r005c02= v200r006c00= v200r007c00= v200r008c00
S12700 FirmwareOperating system
Affected:= v200r005c00= v200r006c00= v200r008c00
S6300 FirmwareOperating system
Affected:= v200r001c00= v200r002c00= v200r003c00= v200r005c00= v200r005c01= v200r005c02= v200r008c00
S7700 FirmwareOperating system
Affected:= v200r001c00= v200r002c00= v200r003c00= v200r005c00= v200r006c00= v200r008c00
S5700 FirmwareOperating system
Affected:= v200r001c00= v200r001c01= v200r002c00= v200r003c00= v200r003c02= v200r005c00= v200r006c00= v200r008c00
S6700 FirmwareOperating system
Affected:= v200r001c00= v200r001c01= v200r002c00= v200r003c00= v200r008c00
S9700 FirmwareOperating system
Affected:= v200r001c00= v200r001c01= v200r002c00= v200r003c00= v200r005c00= v200r006c00= v200r008c00
S9300 FirmwareOperating system
Affected:= v200r001c00= v200r003c00= v200r005c00= v200r006c00= v200r008c00

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify device model
    Execute 'display device' or 'display version' command on the Huawei switch to confirm the model number (S5300, S5700, S6700, S7700, S9300, S9700, S12700, or S6300)
    Affected if Device model matches one of the affected models listed in the CVE (S5300, S5700, S6700, S7700, S9300, S9700, S12700, S6300)
  2. Check firmware version
    Execute 'display version' command and locate the 'VRP' or firmware version information. For affected models, the version format is v200rXXXcYY
    Affected if Installed firmware version exactly matches one of the versions listed for your model in the CVE (e.g., v200r001c00, v200r005c00, v200r008c00, etc.)
  3. Verify packet processing feature is enabled
    Check if packet processing features such as ACLs, traffic policing, or packet filtering are active by running 'display acl' or examining interface configurations with 'display current-configuration interface'
    Affected if The device is processing network traffic (standard operational state) - the vulnerability is triggered by malformed packets reaching the packet processing logic
  4. Monitor memory usage
    Use 'display memory-usage' command to observe memory consumption levels over time, especially after periods of high or abnormal traffic
    Affected if Memory usage shows continuous increase or exhaustion patterns that do not return to baseline, indicating a potential memory leak

A defender is affected if they have a Huawei switch from the listed models running one of the specified firmware versions, as the memory leak can be triggered by malformed packets causing denial of service.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

From vendor data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Apply Huawei firmware patches for affected models. As an interim control, implement traffic filtering or rate limiting at network edges to block malformed packets before they reach affected devices.

Fix this in S5300 Firmware Scoped from the published advisory
  • Consultation6.0 h
  • Implementation12.0 h
  • Testing6.0 h
  • Review / QA3.0 h
27.0 hours of engineering $4,800
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2016-6518 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data