CVE-2020-5253 [Low] | Privilege Escalation in Nethack

CVE-2020-5253 is rated Low Risk (30.3/100): CVSS Low severity, with low exploitation likelihood (EPSS 0.20%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

#	Date	Old EPSS score	New EPSS score	Delta (New - Old)
1	2026-04-25	0.10%	0.20%	+0.10%
2	2025-08-14	0.18%	0.10%	-0.08%
3	2025-05-20	—	0.18%	—

Date

Old EPSS score

New EPSS score

Delta (New - Old)

2026-04-25

0.10%

0.20%

+0.10%

2025-08-14

0.18%

0.10%

-0.08%

2025-05-20

—

0.18%

—

Base score	Version	Severity	Vector	Exploitability	Impact	Score source
3.9	3.1	LOW	`CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:C/C:L/I:L/A:N` 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:H) Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work. Privileges required (PR:L) A normal user session is enough; they don’t have to be admin. User interaction (UI:R) A real person has to do something—click, install, enable—otherwise it doesn’t land. Scope (S:C) Breaking this can reach past the original component and bite other resources—bigger blast radius. Confidentiality (C:L) Some sensitive info could get out, but not a total data dump. Integrity (I:L) Attackers could change some data, but it’s limited—not everything goes. Availability (A:N) Service keeps running; no real outage angle.	0.8	2.7	[email protected]
9.8	3.1	CRITICAL	`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H` 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:N) No account or special rights needed—anonymous or random user is enough. 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:H) They could widely tamper with or forge data—trust in the data is badly hurt. Availability (A:H) Could take the service down hard or make it unusable for people who depend on it.	3.9	5.9	[email protected]
7.5	2.0	HIGH	`AV:N/AC:L/Au:N/C:P/I:P/A:P` Click to expand Access vector (AV:N) Can be exploited remotely over network reachability. Access complexity (AC:L) Exploitation conditions are straightforward and predictable. Authentication (AU:N) No authentication is required. Confidentiality impact (C:P) Partial confidentiality impact. Integrity impact (I:P) Partial integrity impact. Availability impact (A:P) Partial availability impact.	10.0	6.4	[email protected]

Base score

Version

Severity

Vector

Exploitability

Impact

Score source

3.9

3.1

LOW

CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:C/C:L/I:L/A:N 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:H): Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:L): A normal user session is enough; they don’t have to be admin.
User interaction (UI:R): A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:C): Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:L): Some sensitive info could get out, but not a total data dump.
Integrity (I:L): Attackers could change some data, but it’s limited—not everything goes.
Availability (A:N): Service keeps running; no real outage angle.

0.8

2.7

[email protected]

9.8

3.1

CRITICAL

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H 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:N): No account or special rights needed—anonymous or random user is enough.
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:H): They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H): Could take the service down hard or make it unusable for people who depend on it.

3.9

5.9

[email protected]

7.5

2.0

HIGH

AV:N/AC:L/Au:N/C:P/I:P/A:P Click to expand

Access vector (AV:N): Can be exploited remotely over network reachability.
Access complexity (AC:L): Exploitation conditions are straightforward and predictable.
Authentication (AU:N): No authentication is required.
Confidentiality impact (C:P): Partial confidentiality impact.
Integrity impact (I:P): Partial integrity impact.
Availability impact (A:P): Partial availability impact.

10.0

6.4

[email protected]

OS Trackers for CVE-2020-5253

vendor	priority	summary	link
`debian`	not yet assigned	CVE-2020-5253 not yet assigned priority: Debian including 1 source packages (nethack), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5.	https://security-tracker.debian.org/tracker/CVE-2020-5253
`ubuntu`	medium	CVE-2020-5253 medium priority: Ubuntu including 1 source packages (nethack), 17 status rows across 17 suites (bionic, eoan, focal, groovy, hirsute, impish, jammy, kinetic, lunar, mantic, noble, oracular, plucky, questing, trusty, upstream, xenial): not-affected 14, DNE 1, needed 1, released 1.	https://ubuntu.com/security/CVE-2020-5253

Affected software / configurations for CVE-2020-5253

Vendor	Product	Version	Raw CPE
nethack	nethack	< 3.6.0	cpe:2.3:a:nethack:nethack::::::::

References for CVE-2020-5253

URL	Tags
https://github.com/NetHack/NetHack/commits/612755bfb5c412079795c68ba392df5d93874ed8	Patch Third Party Advisory
https://github.com/NetHack/NetHack/security/advisories/GHSA-2c7p-3fj4-223m	Third Party Advisory

URL

CVE-2020-5253 | Privilege escalation in NetHack

Exploit prediction scoring system (EPSS) score for CVE-2020-5253

Common vulnerability scoring system (CVSS) metrics for CVE-2020-5253

Weakness enumeration for CVE-2020-5253

OS Trackers for CVE-2020-5253

Affected software / configurations for CVE-2020-5253

References for CVE-2020-5253