---
id: CVE-2017-6770
title: Multiple Cisco Products OSPF LSA Manipulation Vulnerability (CVE-2017-6770)
summary: >-
  Multiple Cisco products are affected by a vulnerability involving the Open
  Shortest Path First (OSPF) Routing Protocol Link State Advertisement (LSA)
  database. This vulnerability could allow an unauthenticated, remote attacker
  to take full…
severity: medium
cvss: 4.2
cvssVector: 'CVSS:3.0/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:L/A:N/E:F/RL:O/RC:C'
cvssSource: vendor
vendor: Cisco
product: IOS
affected:
  - ios 15.1(2)T
  - ios 12.0(25)SX10
  - ios 12.2(25)SW9
  - ios 12.0(6)
  - ios 12.2(31)XN2
  - ios 12.2(31)SB1a
  - ios 12.2(50)SG3
  - ios 12.3(14)YQ5
  - ios 12.2(25)EWA5
  - ios 12.2(18)SXD7b
  - ios 12.3(4)XD4
  - ios 12.3(11)YF2
  - ios 12.0(31)S5e
  - ios 12.2(2)XT2
  - ios 12.0(11)ST3
  - ios 12.0(32)S1b
  - ios 12.0(25)S1
  - ios 12.2(28)SB10
  - ios 12.4(21a)M1
  - ios 12.4(4)T8
  - ios 12.1(10)EV3
  - ios 12.0(16)S12
  - ios 12.2(20)S10
  - ios 12.0(31)S1d
  - ios 12.2(15)MC1c
  - ios 12.4(20)T1
  - ios 12.2(4)MB7
  - ios 12.3(8)YG7
  - ios 12.4(22)XR5
  - ios 12.2(55)EY
  - ios 12.0(30)S2
  - ios 12.4(15)XY4
  - ios 12.1(3a)XI9
  - ios 12.0(23)S5
  - ios 12.2(25)EWA1
  - ios 12.2(31)SB10c
  - ios 12.2(31)SB9b
  - ios 12.0(13)
  - ios 12.3(8)T9
  - ios 12.0(1)
published: '2017-07-27'
updated: '2017-08-03'
sourceUpdated: '2017-08-03T14:07:00+00:00'
source: CSAF
sourceUrl: >-
  https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20170727-ospf
references:
  - url: >-
      https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20170727-ospf
  - url: 'https://software.cisco.com'
tags:
  - csaf
  - vendor-advisory
  - cisco
epss: 0.01693
epssPercentile: 0.76984
ingestedAt: '2026-10-18T12:01:17.951Z'
---

## Overview

Multiple Cisco products are affected by a vulnerability involving the Open Shortest Path First (OSPF) Routing Protocol Link State Advertisement (LSA) database. This vulnerability could allow an unauthenticated, remote attacker to take full control of the OSPF Autonomous System (AS) domain routing table, allowing the attacker to intercept or black-hole traffic.

The attacker could exploit this vulnerability by injecting crafted OSPF packets. Successful exploitation could cause the targeted router to flush its routing table and propagate the crafted OSPF LSA type 1 update throughout the OSPF AS domain.

To exploit this vulnerability, an attacker must accurately determine certain parameters within the LSA database on the target router. This vulnerability can only be triggered by sending crafted unicast or multicast OSPF LSA type 1 packets. No other LSA type packets can trigger this vulnerability.

The Fabric Shortest Path First (FSPF) protocol is not affected by this vulnerability.

Workarounds that address this vulnerability are available.

## Vendor advisories

- **cisco-sa-20170727-ospf** · Cisco · affected: IOS (3432 versions), Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (337 versions), Cisco NX-OS Software (217 versions), Cisco IOS XE Software (203 versions) · updated 2017-08-03 · [advisory](https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20170727-ospf)

**Multiple Cisco Products OSPF LSA Manipulation Vulnerability**. Released 2017-07-27, updated 2017-08-03.

Affected:

- IOS 15.1(2)T
- IOS 12.0(25)SX10
- IOS 12.2(25)SW9
- IOS 12.0(6)
- IOS 12.2(31)XN2
- IOS 12.2(31)SB1a
- IOS 12.2(50)SG3
- IOS 12.3(14)YQ5
- IOS 12.2(25)EWA5
- IOS 12.2(18)SXD7b
- IOS 12.3(4)XD4
- IOS 12.3(11)YF2
- IOS 12.0(31)S5e
- IOS 12.2(2)XT2
- IOS 12.0(11)ST3
- IOS 12.0(32)S1b
- IOS 12.0(25)S1
- IOS 12.2(28)SB10
- IOS 12.4(21a)M1
- IOS 12.4(4)T8
- IOS 12.1(10)EV3
- IOS 12.0(16)S12
- IOS 12.2(20)S10
- IOS 12.0(31)S1d
- IOS 12.2(15)MC1c
- IOS 12.4(20)T1
- IOS 12.2(4)MB7
- IOS 12.3(8)YG7
- IOS 12.4(22)XR5
- IOS 12.2(55)EY
- IOS 12.0(30)S2
- IOS 12.4(15)XY4
- IOS 12.1(3a)XI9
- IOS 12.0(23)S5
- IOS 12.2(25)EWA1
- IOS 12.2(31)SB10c
- IOS 12.2(31)SB9b
- IOS 12.0(13)
- IOS 12.3(8)T9
- IOS 12.0(1)

## Remediation

Cisco has released software updates that address this vulnerability. https://software.cisco.com