CVE-2023-4911 GNU GNU C Library: 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 Dec 12, 2023
What to do
- Install GNU's security update for GNU C Library. If no update exists, follow the vendor's workaround or stop using the product until one ships.
- Keep a list of every internet-facing server you run so nothing is forgotten.
- Patch anything in this catalog first, ahead of normal patch cycles.
- Put admin and file-transfer apps behind a VPN or single sign-on instead of the open internet.
Who is affected
Work IT. Aimed mostly at company systems — you are affected through the companies you use, not your own phone.
What's at risk: Mass data theft and ransomware: a single flaw in a file-transfer or email server has exposed thousands of organisations at once.
The details
- Official name
- GNU C Library Buffer Overflow Vulnerability
- Product
- GNU GNU C Library
- CISA description
- GNU C Library's dynamic loader ld.so contains a buffer overflow vulnerability when processing the GLIBC_TUNABLES environment variable, allowing a local attacker to execute code with elevated privileges.
- Type of flaw
- Memory-safety flaw (CWE-122)
- Confirmed exploited
- Nov 21, 2023
- US federal patch deadline
- Dec 12, 2023
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Answering about CVE-2023-4911 ·
Questions about CVE-2023-4911
Is CVE-2023-4911 being exploited?
Yes. CISA added CVE-2023-4911 to its Known Exploited Vulnerabilities catalog on Nov 21, 2023, which means there is reliable evidence of real-world attacks.
How do I fix CVE-2023-4911?
Install GNU's security update for GNU C Library. If no update exists, follow the vendor's workaround or stop using the product until one ships. Keep a list of every internet-facing server you run so nothing is forgotten.
Am I affected by CVE-2023-4911?
Only if you use GNU GNU C Library. Aimed mostly at company systems — you are affected through the companies you use, not your own phone.