Security Bulletin: ISC DHCP server for IBM i is vulnerable to a denial of service attack due to a memory leak and refererence count overflow (CVE-2022-2928, CVE-2022-2929)

Summary

ISC DHCP server on IBM i is vulnerable to a denial of service attack due to a memory leak in the fqdn_universe_decode function and a reference count overflow in the add_option function as described in the vulnerability details section. IBM i has addressed the vulnerabilities in ISC DHCP server with a fix as described in the remediation/fixes section.

Vulnerability Details

CVEID:CVE-2022-2929
**DESCRIPTION:**ISC DHCP is vulnerable to a denial of service, caused by a memory leak in the fqdn_universe_decode() function. By sending specially crafted DHCP packets for an extended period of time, a remote attacker from within the local network could exploit this vulnerability to cause the server to run out of memory.
CVSS Base score: 6.5
CVSS Temporal Score: See: https://exchange.xforce.ibmcloud.com/vulnerabilities/237823 for the current score.
CVSS Vector: (CVSS:3.0/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H)

CVEID:CVE-2022-2928
**DESCRIPTION:**ISC DHCP is vulnerable to a denial of service, caused by an option refcount overflow in the add_option() function. A remote attacker from within the local network could exploit this vulnerability to overflow the reference counters and cause the server to abort.
CVSS Base score: 6.5
CVSS Temporal Score: See: https://exchange.xforce.ibmcloud.com/vulnerabilities/237822 for the current score.
CVSS Vector: (CVSS:3.0/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H)

Affected Products and Versions

Remediation/Fixes

The issue can be fixed by applying a PTF to IBM i. IBM i 7.5, 7.4, 7.3, and 7.2 will be fixed.

The IBM i PTF numbers contain the fix for the vulnerabilities.

IBM i Release| 5770-SS1
PTF Number| PTF Download Link
—|—|—
7.5| SI81438| SI81438
7.4| SI81439| SI81439
7.3| SI81440| SI81440
7.2| SI81441| SI81441

https://www.ibm.com/support/fixcentral

_Important note: _IBM recommends that all users running unsupported versions of affected products upgrade to supported and fixed version of affected products.

Workarounds and Mitigations

None