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TI-2021-13727 Aliases CVE-2021-34728GHSA-xgg8-892p-f458

Cisco IOS XR Software Authenticated User Privilege Escalation Vulnerabilities

Priority LOW 36CWE-78Published · Updated

Key facts

Attack vector
Local
Privileges required
Low
User interaction
None
Attack complexity
Low
Impact type
Code execution
Confidentiality · integrity · availability
High · High · High
Fix status
No fix listed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA. Impact type from CWE-78.

Summary

Multiple vulnerabilities in the CLI of Cisco IOS XR Software could allow an authenticated, local attacker with a low-privileged account to elevate privileges on an affected device. For more information about these vulnerabilities, see the Details section of this advisory.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00301 23rd percentileScored 2026-11-07
Fix No fix listed No fixed version in the sources yet

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Total

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
CiscoCisco IOS XR Softwareall versions—No fix listedCNA
  • Cisco IOS XR Software VendorCisco Affected all versions Fixed in — No fix listed CNA

CPE configurations NVD · 46

CPEVersionsRoleVendor
cpe:2.3:o:cisco:ios_xr:*:*:*:*:*:*:*:*before 7.3.2; 7.4.0 to before 7.4.1VulnerableCisco
cpe:2.3:h:cisco:asr_9000v-v2:-:*:*:*:*:*:*:*not specified by NVDRunning onCisco
cpe:2.3:h:cisco:asr_9001:-:*:*:*:*:*:*:*not specified by NVDRunning onCisco
cpe:2.3:h:cisco:asr_9006:-:*:*:*:*:*:*:*not specified by NVDRunning onCisco
cpe:2.3:h:cisco:asr_9010:-:*:*:*:*:*:*:*not specified by NVDRunning onCisco
cpe:2.3:h:cisco:asr_9901:-:*:*:*:*:*:*:*not specified by NVDRunning onCisco
cpe:2.3:h:cisco:asr_9902:-:*:*:*:*:*:*:*not specified by NVDRunning onCisco
cpe:2.3:h:cisco:asr_9903:-:*:*:*:*:*:*:*not specified by NVDRunning onCisco
cpe:2.3:h:cisco:asr_9904:-:*:*:*:*:*:*:*not specified by NVDRunning onCisco
cpe:2.3:h:cisco:asr_9906:-:*:*:*:*:*:*:*not specified by NVDRunning onCisco
  • cpe:2.3:o:cisco:ios_xr:*:*:*:*:*:*:*:* Versions before 7.3.2; 7.4.0 to before 7.4.1 Vulnerable ·Cisco
  • cpe:2.3:h:cisco:asr_9000v-v2:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Cisco
  • cpe:2.3:h:cisco:asr_9001:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Cisco
  • cpe:2.3:h:cisco:asr_9006:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Cisco
  • cpe:2.3:h:cisco:asr_9010:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Cisco
  • cpe:2.3:h:cisco:asr_9901:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Cisco
  • cpe:2.3:h:cisco:asr_9902:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Cisco
  • cpe:2.3:h:cisco:asr_9903:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Cisco
  • cpe:2.3:h:cisco:asr_9904:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Cisco
  • cpe:2.3:h:cisco:asr_9906:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Cisco
Show 36 more CPE
CPEVersionsRoleVendor
cpe:2.3:h:cisco:asr_9910:-:*:*:*:*:*:*:*not specified by NVDRunning onCisco
cpe:2.3:h:cisco:asr_9912:-:*:*:*:*:*:*:*not specified by NVDRunning onCisco
cpe:2.3:h:cisco:asr_9922:-:*:*:*:*:*:*:*not specified by NVDRunning onCisco
cpe:2.3:h:cisco:ios_xrv:-:*:*:*:*:*:*:*not specified by NVDRunning onCisco
cpe:2.3:h:cisco:ios_xrv_9000:-:*:*:*:*:*:*:*not specified by NVDRunning onCisco
cpe:2.3:h:cisco:ncs_520:-:*:*:*:*:*:*:*not specified by NVDRunning onCisco
cpe:2.3:h:cisco:ncs_540:-:*:*:*:*:*:*:*not specified by NVDRunning onCisco
cpe:2.3:h:cisco:ncs_540_fronthaul:-:*:*:*:*:*:*:*not specified by NVDRunning onCisco
cpe:2.3:h:cisco:ncs_560-4:-:*:*:*:*:*:*:*not specified by NVDRunning onCisco
cpe:2.3:h:cisco:ncs_560-7:-:*:*:*:*:*:*:*not specified by NVDRunning onCisco
cpe:2.3:h:cisco:ncs_5001:-:*:*:*:*:*:*:*not specified by NVDRunning onCisco
cpe:2.3:h:cisco:ncs_5002:-:*:*:*:*:*:*:*not specified by NVDRunning onCisco
cpe:2.3:h:cisco:ncs_5011:-:*:*:*:*:*:*:*not specified by NVDRunning onCisco
cpe:2.3:h:cisco:ncs_4009:-:*:*:*:*:*:*:*not specified by NVDRunning onCisco
cpe:2.3:h:cisco:ncs_4016:-:*:*:*:*:*:*:*not specified by NVDRunning onCisco
cpe:2.3:h:cisco:ncs_5501:-:*:*:*:*:*:*:*not specified by NVDRunning onCisco
cpe:2.3:h:cisco:ncs_5501-se:-:*:*:*:*:*:*:*not specified by NVDRunning onCisco
cpe:2.3:h:cisco:ncs_5502:-:*:*:*:*:*:*:*not specified by NVDRunning onCisco
cpe:2.3:h:cisco:ncs_5502-se:-:*:*:*:*:*:*:*not specified by NVDRunning onCisco
cpe:2.3:h:cisco:ncs_5508:-:*:*:*:*:*:*:*not specified by NVDRunning onCisco
cpe:2.3:h:cisco:ncs_5516:-:*:*:*:*:*:*:*not specified by NVDRunning onCisco
cpe:2.3:h:cisco:ncs_6000:-:*:*:*:*:*:*:*not specified by NVDRunning onCisco
cpe:2.3:h:cisco:ncs_6008:-:*:*:*:*:*:*:*not specified by NVDRunning onCisco
cpe:2.3:h:cisco:ncs_1001:-:*:*:*:*:*:*:*not specified by NVDRunning onCisco
cpe:2.3:h:cisco:ncs_1002:-:*:*:*:*:*:*:*not specified by NVDRunning onCisco
cpe:2.3:h:cisco:ncs_1004:-:*:*:*:*:*:*:*not specified by NVDRunning onCisco
cpe:2.3:h:cisco:8101-32fh:-:*:*:*:*:*:*:*not specified by NVDRunning onCisco
cpe:2.3:h:cisco:8101-32h:-:*:*:*:*:*:*:*not specified by NVDRunning onCisco
cpe:2.3:h:cisco:8102-64h:-:*:*:*:*:*:*:*not specified by NVDRunning onCisco
cpe:2.3:h:cisco:8201:-:*:*:*:*:*:*:*not specified by NVDRunning onCisco
cpe:2.3:h:cisco:8201-32fh:-:*:*:*:*:*:*:*not specified by NVDRunning onCisco
cpe:2.3:h:cisco:8202:-:*:*:*:*:*:*:*not specified by NVDRunning onCisco
cpe:2.3:h:cisco:8804:-:*:*:*:*:*:*:*not specified by NVDRunning onCisco
cpe:2.3:h:cisco:8808:-:*:*:*:*:*:*:*not specified by NVDRunning onCisco
cpe:2.3:h:cisco:8812:-:*:*:*:*:*:*:*not specified by NVDRunning onCisco
cpe:2.3:h:cisco:8818:-:*:*:*:*:*:*:*not specified by NVDRunning onCisco
  • cpe:2.3:h:cisco:asr_9910:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Cisco
  • cpe:2.3:h:cisco:asr_9912:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Cisco
  • cpe:2.3:h:cisco:asr_9922:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Cisco
  • cpe:2.3:h:cisco:ios_xrv:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Cisco
  • cpe:2.3:h:cisco:ios_xrv_9000:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Cisco
  • cpe:2.3:h:cisco:ncs_520:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Cisco
  • cpe:2.3:h:cisco:ncs_540:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Cisco
  • cpe:2.3:h:cisco:ncs_540_fronthaul:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Cisco
  • cpe:2.3:h:cisco:ncs_560-4:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Cisco
  • cpe:2.3:h:cisco:ncs_560-7:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Cisco
  • cpe:2.3:h:cisco:ncs_5001:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Cisco
  • cpe:2.3:h:cisco:ncs_5002:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Cisco
  • cpe:2.3:h:cisco:ncs_5011:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Cisco
  • cpe:2.3:h:cisco:ncs_4009:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Cisco
  • cpe:2.3:h:cisco:ncs_4016:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Cisco
  • cpe:2.3:h:cisco:ncs_5501:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Cisco
  • cpe:2.3:h:cisco:ncs_5501-se:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Cisco
  • cpe:2.3:h:cisco:ncs_5502:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Cisco
  • cpe:2.3:h:cisco:ncs_5502-se:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Cisco
  • cpe:2.3:h:cisco:ncs_5508:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Cisco
  • cpe:2.3:h:cisco:ncs_5516:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Cisco
  • cpe:2.3:h:cisco:ncs_6000:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Cisco
  • cpe:2.3:h:cisco:ncs_6008:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Cisco
  • cpe:2.3:h:cisco:ncs_1001:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Cisco
  • cpe:2.3:h:cisco:ncs_1002:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Cisco
  • cpe:2.3:h:cisco:ncs_1004:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Cisco
  • cpe:2.3:h:cisco:8101-32fh:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Cisco
  • cpe:2.3:h:cisco:8101-32h:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Cisco
  • cpe:2.3:h:cisco:8102-64h:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Cisco
  • cpe:2.3:h:cisco:8201:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Cisco
  • cpe:2.3:h:cisco:8201-32fh:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Cisco
  • cpe:2.3:h:cisco:8202:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Cisco
  • cpe:2.3:h:cisco:8804:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Cisco
  • cpe:2.3:h:cisco:8808:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Cisco
  • cpe:2.3:h:cisco:8812:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Cisco
  • cpe:2.3:h:cisco:8818:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Cisco

Remediation

No fixed version listed by the sources yet.

Fixed in the same release

Records fixed by the same vendor advisory or release, as the CNA lists them.

  • Advisory ·

    Cisco IOS XR Software — 20210908 Cisco IOS XR Software Authenticated User Privilege Escalation Vulnerabilities

    2 records Highest priority Priority LOW 2 LOW

    Other records, highest priority first

    • TI-2021-13718 Cisco IOS XR Software Authenticated User Privilege Escalation VulnerabilitiesPriority LOW 36

Timeline

  1. 2026-10-02 Threatist record created from CVE-2021-34728
  2. 2026-10-03 Alias added: GHSA-xgg8-892p-f458

References

  • TI-2020-02680 Cisco IOS XR Software Cisco Discovery Protocol Format String Vulnerability KEVCVSS 3.1HIGH 8.8
  • TI-2018-00135 Memory corruption in Cisco IOS, IOS XE, and IOS XR KEVCVSS 3.1HIGH 8.8
  • TI-2020-03113 Cisco IOS XR Software DVMRP Memory Exhaustion Vulnerabilities KEVCVSS 3.1HIGH 8.6
  • TI-2020-03110 Cisco IOS XR Software DVMRP Memory Exhaustion Vulnerability KEVCVSS 3.1HIGH 8.6
  • TI-2018-00142 Memory corruption in Cisco IOS, IOS XE, and IOS XR KEVCVSS 3.1HIGH 8.0
  • TI-2023-23979 The HTTP/2 protocol allows a denial of service (server resource consumption) because… KEVCVSS 3.1HIGH 7.5
See all 199 →

Sources