Cisco IOS XR Software DVMRP Memory Exhaustion Vulnerabilities
Multiple vulnerabilities in the Distance Vector Multicast Routing Protocol (DVMRP) feature of Cisco IOS XR Software could allow an unauthenticated, remote attacker to either immediately crash the Internet Group Management Protocol (IGMP) process or make it consume available memory and eventually crash. The memory consumption may negatively impact other processes that are running on the device. These vulnerabilities are due to the incorrect handling of IGMP packets. An attacker could exploit these vulnerabilities by sending crafted IGMP traffic to an affected device. A successful exploit could allow the attacker to immediately crash the IGMP process or cause memory exhaustion, resulting in other processes becoming unstable. These processes may include, but are not limited to, interior and exterior routing protocols. Cisco will release software updates that address these vulnerabilities.
- Published
- Sep 22, 2020
- Updated
- Jun 16, 2026
- EPSS
- 3.3% · 88th percentile
- CWE
- CWE-400
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Report tools
Action score
65
This week
Don’t wait for the next maintenance window.
- CVSS
- 34 / 40 · 8.6 / 10
- CISA KEV
- 30 / 30 · Listed
- EPSS
- 1 / 30 · 3.3%
CISA SSVC decision
- Exploitation
- active
- Automatable
- yes
- Technical impact
- partial
Vulnrichment: CISA's decision-tree inputs.
CNA vs NVD score
- NVD
- 8.6
- CNA · cisco
- 8.6
- agree
The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.
Actively exploited in the wild
CISA added this to its Known Exploited Vulnerabilities catalog on Nov 3, 2021. That signals real attacks, not theory.
Remediation deadline for government agencies: May 3, 2022.
Affected systems
| Vendor | Product | CPE |
|---|---|---|
| cisco | crs-1 16-slot single-shelf system | cpe:2.3:h:cisco:crs-1_16-slot_single-shelf_system |
| cisco | ios xr | cpe:2.3:o:cisco:ios_xr |
| cisco | asr 9000v | cpe:2.3:h:cisco:asr_9000v |
| cisco | asr 9001 | cpe:2.3:h:cisco:asr_9001 |
| cisco | asr 9006 | cpe:2.3:h:cisco:asr_9006 |
| cisco | asr 9010 | cpe:2.3:h:cisco:asr_9010 |
| cisco | asr 9901 | cpe:2.3:h:cisco:asr_9901 |
| cisco | asr 9903 | cpe:2.3:h:cisco:asr_9903 |
| cisco | asr 9904 | cpe:2.3:h:cisco:asr_9904 |
| cisco | asr 9906 | cpe:2.3:h:cisco:asr_9906 |
| cisco | asr 9910 | cpe:2.3:h:cisco:asr_9910 |
| cisco | asr 9912 | cpe:2.3:h:cisco:asr_9912 |
and 31 more
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- cisco ios xrbefore 6.5.2
- cisco ios xr6.1.4
- cisco ios xr6.2.3
- cisco ios xr6.3.3
- cisco ios xr6.4.2
- cisco ios xr6.4.3
- cisco ios xr6.5.3
- cisco ios xr6.6.2
- cisco ios xr6.6.3
- cisco ios xr7.0.2
- cisco ios xr7.1.15
- cisco ios xr7.1.2
Versions reported by the vendor
Affected version ranges reported by the assigning authority (cisco). Independent of NVD's CPE analysis and usually ahead of it.
Cisco Cisco IOS XR Software
- n/aaffected
Same product
cisco: all recordsOther highest-scoring records for the same primary product.
- CVE-2020-3118Cisco IOS XR Software Cisco Discovery Protocol Format String VulnerabilityKEV69This week
- CVE-2020-3566Cisco IOS XR Software DVMRP Memory Exhaustion VulnerabilityKEV65This week
- CVE-2010-3035Cisco IOS XR 3.4.0 through 3.9.1, when BGP is enabled, does not properly handle unrecognized transitive attributes, which allows remote attaKEV62This week
- CVE-2022-20821Cisco IOS XR Software Health Check Open Port VulnerabilityKEV59Plan
- CVE-2009-2055Cisco IOS XR 3.4.0 through 3.8.1 allows remote attackers to cause a denial of service (session reset) via a BGP UPDATE message with an invalKEV54Plan
- CVE-2019-1710Cisco IOS XR 64-Bit Software for Cisco ASR 9000 Series Aggregation Services Routers Network Isolation Vulnerability40Plan
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
No fix version is recorded for this entry. Check the references for vendor advisories.
Exploit status
Weaponized
A ready exploit tool or active in-the-wild use is known for this vulnerability. This should be your top priority.
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
- Published
- CISA KEV+406 d
- TodaySep 29, 2026+2198 d
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
No commit or PR link among the references.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
No credits in the CNA record.
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
No nightly-computed relations.
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
—
Bug bounty scope
No known public program.
Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).
Technical details
Attack conditions
- Anyone who can reach it over the internet can trigger it.
- No account or password is required.
- No user action is required.
- No special conditions are required; it is repeatable.
If successful
- Confidentiality
- none
- Integrity
- none
- Availability
- high · the service can be disrupted
Impact can extend beyond the vulnerable component (scope changes).
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- None
- Scope
- Changed
- Confidentiality impact
- None
- Integrity impact
- None
- Availability impact
- High
Weakness class (CWE)
CWE-400 · Uncontrolled Resource ConsumptionCVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
nvd-primary
Root cause
Code that parses nested structures sets no depth or size limit. A small input can turn into a disproportionate processing load.
The bug in code
The whole CWE-400 classA representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.
Vulnerable
function expand(node) { return node.children.map(expand);}Fixed
const MAX_DEPTH = 32;function expand(node, depth = 0) { if (depth > MAX_DEPTH) throw new Error("too deep"); return node.children.map((c) => expand(c, depth + 1));}Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
Noroxi analysis
No Noroxi analysis for this record yet
We don't hand-write analysis for all 385,000+ vulnerabilities; that wouldn't be honest. For notable, high-impact vulnerabilities our team writes the mechanism, detection and remediation steps.
We use this product, ask for helpChange log
No changes recorded on tracked fields yet. Score, KEV, exploit maturity and fix status changes appear here.
References
- tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-iosxr-dvmrp-memexh-dSmpdvfz
- www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2020-3569
Vendor advisories and official records. Exploit/PoC links are deliberately left out.