CVE-2023-20109 Cisco IOS and IOS XE: memory-safety flaw
In plain words: The program mishandles the memory it uses to keep track of data. A specially made input can scramble that memory. Usually lets an attacker crash the program or run their own code with its permissions.
Confirmed exploited by CISA on · US federal patch deadline Oct 31, 2023
What to do
- Install Cisco's security update for IOS and IOS XE. If no update exists, follow the vendor's workaround or stop using the product until one ships.
- Install system updates the day they come out — most phone zero-days are fixed in a point release.
- Restart your phone every few days; some spyware does not survive a reboot.
- If you are a journalist, activist, lawyer, politician or executive, turn on Lockdown Mode (iPhone) or Advanced Protection (Android).
Who is affected
Could reach you. This one is aimed at devices or apps of the kind people own.
What's at risk: Messages, photos, location, microphone and camera. The most serious ones are "zero-click": no tap needed from the owner. They are usually used as spyware against a small number of chosen people.
The details
- Official name
- Cisco IOS and IOS XE Group Encrypted Transport VPN Out-of-Bounds Write Vulnerability
- Product
- Cisco IOS and IOS XE
- CISA description
- Cisco IOS and IOS XE contain an out-of-bounds write vulnerability in the Group Encrypted Transport VPN (GET VPN) feature that could allow an authenticated, remote attacker who has administrative control of either a group member or a key server to execute malicious code or cause a device to crash.
- Type of flaw
- Memory-safety flaw (CWE-787)
- Confirmed exploited
- Oct 10, 2023
- US federal patch deadline
- Oct 31, 2023
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Answering about CVE-2023-20109 ·
Questions about CVE-2023-20109
Is CVE-2023-20109 being exploited?
Yes. CISA added CVE-2023-20109 to its Known Exploited Vulnerabilities catalog on Oct 10, 2023, which means there is reliable evidence of real-world attacks.
How do I fix CVE-2023-20109?
Install Cisco's security update for IOS and IOS XE. If no update exists, follow the vendor's workaround or stop using the product until one ships. Install system updates the day they come out — most phone zero-days are fixed in a point release.
Am I affected by CVE-2023-20109?
Only if you use Cisco IOS and IOS XE. This one is aimed at devices or apps of the kind people own.