CVE-2021-25217 Detail

Current Description

In ISC DHCP 4.1-ESV-R1 -> 4.1-ESV-R16, ISC DHCP 4.4.0 -> 4.4.2 (Other branches of ISC DHCP (i.e., releases in the 4.0.x series or lower and releases in the 4.3.x series) are beyond their End-of-Life (EOL) and no longer supported by ISC. From inspection it is clear that the defect is also present in releases from those series, but they have not been officially tested for the vulnerability), The outcome of encountering the defect while reading a lease that will trigger it varies, according to: the component being affected (i.e., dhclient or dhcpd) whether the package was built as a 32-bit or 64-bit binary whether the compiler flag -fstack-protection-strong was used when compiling In dhclient, ISC has not successfully reproduced the error on a 64-bit system. However, on a 32-bit system it is possible to cause dhclient to crash when reading an improper lease, which could cause network connectivity problems for an affected system due to the absence of a running DHCP client process. In dhcpd, when run in DHCPv4 or DHCPv6 mode: if the dhcpd server binary was built for a 32-bit architecture AND the -fstack-protection-strong flag was specified to the compiler, dhcpd may exit while parsing a lease file containing an objectionable lease, resulting in lack of service to clients. Additionally, the offending lease and the lease immediately following it in the lease database may be improperly deleted. if the dhcpd server binary was built for a 64-bit architecture OR if the -fstack-protection-strong compiler flag was NOT specified, the crash will not occur, but it is possible for the offending lease and the lease which immediately followed it to be improperly deleted.


View Analysis Description

Severity



CVSS 3.x Severity and Metrics:

NIST CVSS score matches with CNA score
CNA:  Internet Systems Consortium (ISC)
Base Score:  7.4 HIGH
Vector:  CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H


NVD Analysts use publicly available information to associate vector strings and CVSS scores. We also display any CVSS information provided within the CVE List from the CNA.

Note: The NVD and the CNA have provided the same score. When this occurs only the CNA information is displayed, but the Acceptance Level icon for the CNA is given a checkmark to signify NVD concurrence.

References to Advisories, Solutions, and Tools

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Hyperlink Resource
http://www.openwall.com/lists/oss-security/2021/05/26/6 Mailing List  Patch  Third Party Advisory 
https://kb.isc.org/docs/cve-2021-25217 Exploit  Vendor Advisory 
https://lists.debian.org/debian-lts-announce/2021/06/msg00002.html Mailing List  Third Party Advisory 
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/5QI4DYC7J4BGHEW3NH4XHMWTHYC36UK4/ Mailing List  Third Party Advisory 
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/Z2LB42JWIV4M4WDNXX5VGIP26FEYWKIF/ Mailing List  Third Party Advisory 

Weakness Enumeration

CWE-ID CWE Name Source
CWE-119 Improper Restriction of Operations within the Bounds of a Memory Buffer cwe source acceptance level NIST  

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Change History

5 change records found show changes

Quick Info

CVE Dictionary Entry:
CVE-2021-25217
NVD Published Date:
05/26/2021
NVD Last Modified:
06/09/2021
Source:
Internet Systems Consortium (ISC)