CVE-2023-3341: A stack exhaustion flaw in control channel code may cause named to terminate unexpectedly
Document version: 2.0
Posting date: 20 September 2023
Program impacted: BIND 9
- 9.2.0 -> 9.16.43
- 9.18.0 -> 9.18.18
- 9.19.0 -> 9.19.16
(Versions prior to 9.11.37 were not assessed.)
BIND Supported Preview Edition
- 9.9.3-S1 -> 9.16.43-S1
- 9.18.0-S1 -> 9.18.18-S1
(Versions prior to 9.11.37-S1 were not assessed.)
The code that processes control channel messages sent to
named calls certain functions recursively during packet parsing. Recursion depth is only limited by the maximum accepted packet size; depending on the environment, this may cause the packet-parsing code to run out of available stack memory, causing
named to terminate unexpectedly. Since each incoming control channel message is fully parsed before its contents are authenticated, exploiting this flaw does not require the attacker to hold a valid RNDC key; only network access to the control channel's configured TCP port is necessary.
By sending a specially crafted message over the control channel, an attacker can cause the packet-parsing code to run out of available stack memory, causing
named to terminate unexpectedly. However, the attack only works in environments where the stack size available to each process/thread is small enough; the exact threshold depends on multiple factors and is therefore impossible to specify universally.
CVSS Score: 7.5
CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
For more information on the Common Vulnerability Scoring System and to obtain your specific environmental score please visit: https://nvd.nist.gov/vuln-metrics/cvss/v3-calculator?vector=AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H&version=3.1.
named only allows control-channel connections over the loopback interface, making this attack impossible to carry out over the network. When enabling remote access to the control channel's configured TCP port, care should be taken to limit such access to trusted IP ranges on the network level, effectively preventing unauthorized parties from carrying out the attack described in this advisory.
We are not aware of any active exploits.
Upgrade to the patched release most closely related to your current version of BIND 9:
BIND Supported Preview Edition is a special feature preview branch of BIND provided to eligible ISC support customers.
ISC would like to thank Eric Sesterhenn from X41 D-Sec GmbH for bringing this vulnerability to our attention.
Document revision history:
- 1.0 Early Notification, 13 September 2023
- 2.0 Public disclosure, 20 September 2023
See our BIND 9 Security Vulnerability Matrix for a complete listing of security vulnerabilities and versions affected.
Do you still have questions? Questions regarding this advisory should be mailed to [email protected] or posted as confidential GitLab issues at https://gitlab.isc.org/isc-projects/bind9/-/issues/new?issue[confidential]=true.
ISC patches only currently supported versions. When possible we indicate EOL versions affected. For current information on which versions are actively supported, please see https://www.isc.org/download/.
ISC Security Vulnerability Disclosure Policy:
Details of our current security advisory policy and practice can be found in the ISC Software Defect and Security Vulnerability Disclosure Policy at https://kb.isc.org/docs/aa-00861.
The Knowledgebase article https://kb.isc.org/docs/cve-2023-3341 is the complete and official security advisory document.
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