CVE-2023-4527: Glibc: stack read overflow in getaddrinfo in no-aaaa mode
A flaw was found in glibc. When the getaddrinfo function is called with the AFUNSPEC address family and the system is configured with no-aaaa mode via /etc/resolv.conf, a DNS response via TCP larger than 2048 bytes can potentially disclose stack contents through the function returned address data, and may cause a crash.
Other sources
glibc is vulnerable to a stack-based buffer overflow, caused by improper bounds checking by the getaddrinfo function. By sending a DNS response over TCP larger than 2048 bytes, a remote attacker could overflow a buffer, allowing an attacker to obtain sensitive information or cause a denial of service.
— IBM
Glibc: stack read overflow in getaddrinfo in no-aaaa mode
— Microsoft
If the system is configured in no-aaaa mode via /etc/resolv.conf, getaddrinfo is called for the AFUNSPEC address family, and a DNS response is received over TCP that is larger than 2048 bytes, getaddrinfo may potentially disclose stack contents via the returned address data, or crash. While name lookup normally just fails incorrectly, crashes are not difficult to trigger, with valid DNS responses that are propagated by DNS resolvers.
Reference: https://sourceware.org/bugzilla/showbug.cgi?id=30842
— Red Hat
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
debian/glibcto a version that resolves this vulnerability.Fixed in 2.28-10+deb10u1Fixed in 2.28-10+deb10u2Fixed in 2.31-13+deb11u6Fixed in 2.31-13+deb11u7Fixed in 2.36-9+deb12u3Fixed in 2.37-12 - Upgrade
Upgrade
ubuntu/glibcto a version that resolves this vulnerability.Fixed in 2.37-0ubuntu2.1 - Upgrade
Upgrade
ubuntu/glibcto a version that resolves this vulnerability.Fixed in 2.38-1ubuntu5
Event History
Frequently Asked Questions
What is CVE-2023-4527?
CVE-2023-4527 is a vulnerability found in glibc that allows for a stack read overflow in the getaddrinfo function.
What is the severity of CVE-2023-4527?
CVE-2023-4527 has a severity score of 8.2, indicating a high severity.
How does CVE-2023-4527 affect GNU glibc?
CVE-2023-4527 affects GNU glibc up to version 2.39.
How does CVE-2023-4527 affect Redhat Enterprise Linux?
CVE-2023-4527 affects Redhat Enterprise Linux versions 8.0 and 9.0.
How can CVE-2023-4527 be fixed?
Updating to a version of glibc that is not affected by CVE-2023-4527 is recommended.