CVE-2023-52977 [Medium] | Information Disclosure in Linux Kernel

In the Linux kernel, the following vulnerability has been resolved: net: openvswitch: fix flow memory leak in ovs_flow_cmd_new Syzkaller reports a memory leak of new_flow in ovs_flow_cmd_new() as it is not freed when an allocation of a key fails. BUG: memory leak unreferenced object 0xffff888116668000 (size 632): comm "syz-executor231", pid 1090, jiffies 4294844701 (age 18.871s) hex dump (first 32 bytes): 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ backtrace: [<00000000defa3494>] kmem_cache_zalloc include/linux/slab.h:654 [inline] [<00000000defa3494>] ovs_flow_alloc+0x19/0x180 net/openvswitch/flow_table.c:77 [<00000000c67d8873>] ovs_flow_cmd_new+0x1de/0xd40 net/openvswitch/datapath.c:957 [<0000000010a539a8>] genl_family_rcv_msg_doit+0x22d/0x330 net/netlink/genetlink.c:739 [<00000000dff3302d>] genl_family_rcv_msg net/netlink/genetlink.c:783 [inline] [<00000000dff3302d>] genl_rcv_msg+0x328/0x590 net/netlink/genetlink.c:800 [<000000000286dd87>] netlink_rcv_skb+0x153/0x430 net/netlink/af_netlink.c:2515 [<0000000061fed410>] genl_rcv+0x24/0x40 net/netlink/genetlink.c:811 [<000000009dc0f111>] netlink_unicast_kernel net/netlink/af_netlink.c:1313 [inline] [<000000009dc0f111>] netlink_unicast+0x545/0x7f0 net/netlink/af_netlink.c:1339 [<000000004a5ee816>] netlink_sendmsg+0x8e7/0xde0 net/netlink/af_netlink.c:1934 [<00000000482b476f>] sock_sendmsg_nosec net/socket.c:651 [inline] [<00000000482b476f>] sock_sendmsg+0x152/0x190 net/socket.c:671 [<00000000698574ba>] ____sys_sendmsg+0x70a/0x870 net/socket.c:2356 [<00000000d28d9e11>] ___sys_sendmsg+0xf3/0x170 net/socket.c:2410 [<0000000083ba9120>] __sys_sendmsg+0xe5/0x1b0 net/socket.c:2439 [<00000000c00628f8>] do_syscall_64+0x30/0x40 arch/x86/entry/common.c:46 [<000000004abfdcf4>] entry_SYSCALL_64_after_hwframe+0x61/0xc6 To fix this the patch rearranges the goto labels to reflect the order of object allocations and adds appropriate goto statements on the error paths. Found by Linux Verification Center (linuxtesting.org) with Syzkaller.

#	Date	Old EPSS score	New EPSS score	Delta (New - Old)
1	2025-08-23	0.05%	0.03%	-0.02%
2	2025-07-27	0.02%	0.05%	+0.03%
3	2025-03-28	—	0.02%	—

Date

Old EPSS score

New EPSS score

Delta (New - Old)

2025-08-23

0.05%

0.03%

-0.02%

2025-07-27

0.02%

0.05%

+0.03%

2025-03-28

—

0.02%

—

Base score	Version	Severity	Vector	Exploitability	Impact	Score source
5.5	3.1	MEDIUM	`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H` Click to expand Attack vector (AV:L) They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by. Attack complexity (AC:L) Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup. Privileges required (PR:L) A normal user session is enough; they don’t have to be admin. User interaction (UI:N) Nobody has to click “OK” or open a trap file; it can work without a victim helping. Scope (S:U) Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems. Confidentiality (C:N) Doesn’t really leak secrets in a meaningful way. Integrity (I:N) Data isn’t meaningfully altered or forged. Availability (A:H) Could take the service down hard or make it unusable for people who depend on it.	1.8	3.6	[email protected]
5.5	3.1	MEDIUM	`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H` Click to expand Attack vector (AV:L) They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by. Attack complexity (AC:L) Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup. Privileges required (PR:L) A normal user session is enough; they don’t have to be admin. User interaction (UI:N) Nobody has to click “OK” or open a trap file; it can work without a victim helping. Scope (S:U) Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems. Confidentiality (C:N) Doesn’t really leak secrets in a meaningful way. Integrity (I:N) Data isn’t meaningfully altered or forged. Availability (A:H) Could take the service down hard or make it unusable for people who depend on it.	1.8	3.6	134c704f-9b21-4f2e-91b3-4a467353bcc0

Base score

Version

Severity

Vector

Exploitability

Impact

Score source

5.5

3.1

MEDIUM

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H Click to expand

Attack vector (AV:L): They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L): Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L): A normal user session is enough; they don’t have to be admin.
User interaction (UI:N): Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U): Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N): Doesn’t really leak secrets in a meaningful way.
Integrity (I:N): Data isn’t meaningfully altered or forged.
Availability (A:H): Could take the service down hard or make it unusable for people who depend on it.

1.8

3.6

[email protected]

5.5

3.1

MEDIUM

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H Click to expand

Attack vector (AV:L): They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L): Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L): A normal user session is enough; they don’t have to be admin.
User interaction (UI:N): Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U): Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N): Doesn’t really leak secrets in a meaningful way.
Integrity (I:N): Data isn’t meaningfully altered or forged.
Availability (A:H): Could take the service down hard or make it unusable for people who depend on it.

1.8

3.6

134c704f-9b21-4f2e-91b3-4a467353bcc0

OS Trackers for CVE-2023-52977

vendor	priority	summary	link
`debian`	not yet assigned	CVE-2023-52977 not yet assigned priority: Debian including 1 source packages (linux), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5.	https://security-tracker.debian.org/tracker/CVE-2023-52977
`redhat`	medium	—	https://access.redhat.com/security/cve/CVE-2023-52977
`suse`	medium	CVE-2023-52977 severity moderate: SUSE including 75 source package names (bpftool-4.18.0-513.5.1.el8_9, bpftool-7.2.0-362.8.1.el9_3, …), 288 product×package rows across 46 product lines (SLES-LTSS-TERADATA 15 SP2, SUSE Liberty Linux 8, … (46 product lines)): Known Not Affected 239, Fixed 49.	https://www.suse.com/security/cve/CVE-2023-52977/
`ubuntu`	medium	CVE-2023-52977 medium priority: Ubuntu including 158 source packages (linux, linux-allwinner-5.19, …), 1551 status rows across 10 suites (bionic, focal, jammy, noble, oracular, plucky, questing, trusty, upstream, xenial): DNE 1145, released 153, ignored 146, not-affected 106, needs-triage 1.	https://ubuntu.com/security/CVE-2023-52977

Affected software / configurations for CVE-2023-52977

Vendor	Product	Version	Raw CPE
linux	linux_kernel	>= 4.9.337, < 4.10	cpe:2.3:o:linux:linux_kernel::::::::
linux	linux_kernel	>= 4.14.303, < 4.14.306	cpe:2.3:o:linux:linux_kernel::::::::
linux	linux_kernel	>= 4.19.270, < 4.19.273	cpe:2.3:o:linux:linux_kernel::::::::
linux	linux_kernel	>= 5.4.229, < 5.4.232	cpe:2.3:o:linux:linux_kernel::::::::
linux	linux_kernel	>= 5.10.163, < 5.10.168	cpe:2.3:o:linux:linux_kernel::::::::
linux	linux_kernel	>= 5.15.86, < 5.15.93	cpe:2.3:o:linux:linux_kernel::::::::
linux	linux_kernel	>= 6.0.16, < 6.1	cpe:2.3:o:linux:linux_kernel::::::::
linux	linux_kernel	>= 6.1.2, < 6.1.11	cpe:2.3:o:linux:linux_kernel::::::::

References for CVE-2023-52977

URL	Tags
https://git.kernel.org/stable/c/0c598aed445eb45b0ee7ba405f7ece99ee349c30	Patch
https://git.kernel.org/stable/c/1ac653cf886cdfc082708c82dc6ac6115cebd2ee	Patch
https://git.kernel.org/stable/c/70154489f531587996f3e9d7cceeee65cff0001d	Patch
https://git.kernel.org/stable/c/70d40674a549d498bd63d5432acf46205da1534b	Patch
https://git.kernel.org/stable/c/af4e720bc00a2653f7b9df21755b9978b3d7f386	Patch
https://git.kernel.org/stable/c/ed6c5e8caf55778500202775167e8ccdb1a030cb	Patch
https://git.kernel.org/stable/c/f423c2efd51d7eb1d143c2be7eea233241d9bbbf	Patch

URL

CVE-2023-52977 | net: openvswitch: fix flow memory leak in ovs_flow_cmd_new

Exploit prediction scoring system (EPSS) score for CVE-2023-52977

Common vulnerability scoring system (CVSS) metrics for CVE-2023-52977

Weakness enumeration for CVE-2023-52977

OS Trackers for CVE-2023-52977

Affected software / configurations for CVE-2023-52977

References for CVE-2023-52977