CVE-2024-52518 [Medium] | Authentication Bypass in Nextcloud Server

Nextcloud Server is a self hosted personal cloud system. After an attacker got access to the session of a user or administrator, the attacker would be able to create, change or delete external storages without having to confirm the password. It is recommended that the Nextcloud Server is upgraded to 28.0.12, 29.0.9 or 30.0.2.

#	Date	Old EPSS score	New EPSS score	Delta (New - Old)
1	2026-06-15	0.09%	0.53%	+0.44%
2	2025-09-01	0.05%	0.09%	+0.04%
3	2025-08-05	—	0.05%	—

Date

Old EPSS score

New EPSS score

Delta (New - Old)

2026-06-15

0.09%

0.53%

+0.44%

2025-09-01

0.05%

0.09%

+0.04%

2025-08-05

—

0.05%

—

Base score	Version	Severity	Vector	Exploitability	Impact	Score source
4.4	3.1	MEDIUM	`CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:N/A:N` Click to expand Attack vector (AV:N) Could be attacked over the internet or any normal routed network—not just someone sitting at the machine. Attack complexity (AC:H) Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work. Privileges required (PR:H) They need powerful rights—admin, root, or similar—before this pays off. 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:H) Serious risk that confidential data gets exposed in a big way. Integrity (I:N) Data isn’t meaningfully altered or forged. Availability (A:N) Service keeps running; no real outage angle.	0.7	3.6	[email protected]
5.4	3.1	MEDIUM	`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:L` Click to expand Attack vector (AV:N) Could be attacked over the internet or any normal routed network—not just someone sitting at the machine. 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:L) Attackers could change some data, but it’s limited—not everything goes. Availability (A:L) Might cause slowdowns, glitches, or partial disruption—not a full brick.	2.8	2.5	[email protected]

Base score

Version

Severity

Vector

Exploitability

Impact

Score source

4.4

3.1

MEDIUM

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

Attack vector (AV:N): Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:H): Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:H): They need powerful rights—admin, root, or similar—before this pays off.
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:H): Serious risk that confidential data gets exposed in a big way.
Integrity (I:N): Data isn’t meaningfully altered or forged.
Availability (A:N): Service keeps running; no real outage angle.

0.7

3.6

[email protected]

5.4

3.1

MEDIUM

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

Attack vector (AV:N): Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
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:L): Attackers could change some data, but it’s limited—not everything goes.
Availability (A:L): Might cause slowdowns, glitches, or partial disruption—not a full brick.

2.8

2.5

[email protected]

Affected software / configurations for CVE-2024-52518

Vendor	Product	Version	Raw CPE
nextcloud	nextcloud_server	>= 28.0.0, < 28.0.12	cpe:2.3:a:nextcloud:nextcloud_server:::::-:::*
nextcloud	nextcloud_server	>= 28.0.0, < 28.0.12	cpe:2.3:a:nextcloud:nextcloud_server:::::enterprise:::*
nextcloud	nextcloud_server	>= 29.0.0, < 29.0.9	cpe:2.3:a:nextcloud:nextcloud_server:::::-:::*
nextcloud	nextcloud_server	>= 29.0.0, < 29.0.9	cpe:2.3:a:nextcloud:nextcloud_server:::::enterprise:::*
nextcloud	nextcloud_server	>= 30.0.0, < 30.0.2	cpe:2.3:a:nextcloud:nextcloud_server:::::-:::*
nextcloud	nextcloud_server	>= 30.0.0, < 30.0.2	cpe:2.3:a:nextcloud:nextcloud_server:::::enterprise:::*

References for CVE-2024-52518

URL	Tags
https://github.com/nextcloud/security-advisories/security/advisories/GHSA-vrhf-532w-99rg	Vendor Advisory
https://github.com/nextcloud/server/pull/48373	Issue Tracking
https://github.com/nextcloud/server/pull/48788	Issue Tracking
https://github.com/nextcloud/server/pull/48992	Issue Tracking
https://hackerone.com/reports/2602973	Permissions Required

URL

CVE-2024-52518 | Nextcloud Server is missing password confirmation when changing external storage options

Exploit prediction scoring system (EPSS) score for CVE-2024-52518

Common vulnerability scoring system (CVSS) metrics for CVE-2024-52518

Weakness enumeration for CVE-2024-52518

Affected software / configurations for CVE-2024-52518

References for CVE-2024-52518