Bug 2048934 (CVE-2021-45952) - CVE-2021-45952 dnsmasq: a heap-based buffer overflow in dhcp_reply
Summary: CVE-2021-45952 dnsmasq: a heap-based buffer overflow in dhcp_reply
Keywords:
Status: CLOSED NOTABUG
Alias: CVE-2021-45952
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
high
high
Target Milestone: ---
Assignee: Red Hat Product Security
QA Contact:
URL:
Whiteboard:
Depends On: 2048935
Blocks: 2048923
TreeView+ depends on / blocked
 
Reported: 2022-02-01 08:30 UTC by Marian Rehak
Modified: 2022-05-24 23:42 UTC (History)
16 users (show)

Fixed In Version:
Doc Type: If docs needed, set a value
Doc Text:
Clone Of:
Environment:
Last Closed: 2022-05-24 23:42:39 UTC


Attachments (Terms of Use)

Description Marian Rehak 2022-02-01 08:30:48 UTC
A heap-based buffer overflow in dhcp_reply (called from dhcp_packet and FuzzDhcp).

Reference:

https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=35870
https://github.com/google/oss-fuzz-vulns/blob/main/vulns/dnsmasq/OSV-2021-927.yaml

Comment 1 Marian Rehak 2022-02-01 08:31:05 UTC
Created dnsmasq tracking bugs for this issue:

Affects: fedora-all [bug 2048935]

Comment 5 Petr Menšík 2022-02-17 02:33:34 UTC
It seems this is again bogus report. void dhcp_common_init(void) always initializes daemon->dhcp_packet to sizeof(struct dhcp_packet) size. But fuzzers allocates only fixed 300 bytes, which is not enough. clear_packet() clears whole buffer regardless how large incoming packet was. It requires full buffer therefore.


Note You need to log in before you can comment on or make changes to this bug.