CVE-2020-29129 [Medium] | Out-of-bounds Read in Libslirp

CVE-2020-29129 is rated Low Risk (37.1/100): CVSS Medium severity, with medium exploitation likelihood (EPSS 0.34%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

#	Date	Old EPSS score	New EPSS score	Delta (New - Old)
1	2025-12-02	0.22%	0.34%	+0.12%
2	2025-11-21	0.52%	0.22%	-0.30%
3	2025-11-18	—	0.52%	—

Date

Old EPSS score

New EPSS score

Delta (New - Old)

2025-12-02

0.22%

0.34%

+0.12%

2025-11-21

0.52%

0.22%

-0.30%

2025-11-18

—

0.52%

—

Base score	Version	Severity	Vector	Exploitability	Impact	Score source
4.3	3.1	MEDIUM	`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/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: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:L) Some sensitive info could get out, but not a total data dump. Integrity (I:N) Data isn’t meaningfully altered or forged. Availability (A:N) Service keeps running; no real outage angle.	2.8	1.4	[email protected]
4.0	2.0	MEDIUM	`AV:N/AC:L/Au:S/C:P/I:N/A:N` 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:S) A single authentication is required. Confidentiality impact (C:P) Partial confidentiality impact. Integrity impact (I:N) No integrity impact. Availability impact (A:N) No availability impact.	8.0	2.9	[email protected]

Base score

Version

Severity

Vector

Exploitability

Impact

Score source

4.3

3.1

MEDIUM

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/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: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:L): Some sensitive info could get out, but not a total data dump.
Integrity (I:N): Data isn’t meaningfully altered or forged.
Availability (A:N): Service keeps running; no real outage angle.

2.8

1.4

[email protected]

4.0

2.0

MEDIUM

AV:N/AC:L/Au:S/C:P/I:N/A:N 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:S): A single authentication is required.
Confidentiality impact (C:P): Partial confidentiality impact.
Integrity impact (I:N): No integrity impact.
Availability impact (A:N): No availability impact.

8.0

2.9

[email protected]

OS Trackers for CVE-2020-29129

vendor	priority	summary	link
`alpine`	medium	CVE-2020-29129: 1 source package rows (libslirp); 11 state rows across 7 repos (3.17-community, 3.18-community, 3.19-community, 3.20-community, 3.21-community, 3.22-community, edge-community); fixed 7, open 4.	https://security.alpinelinux.org/vuln/CVE-2020-29129
`debian`	not yet assigned	CVE-2020-29129 not yet assigned priority: Debian including 2 source packages (libslirp, qemu), 10 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 10.	https://security-tracker.debian.org/tracker/CVE-2020-29129
`redhat`	low	—	https://access.redhat.com/security/cve/CVE-2020-29129
`suse`	medium	CVE-2020-29129 severity moderate: SUSE including 842 source package names (0.38.1.5.8.40:qemu-4.2.1-11.16.3, 0.38.1.5.8.40:qemu-ipxe-1.0.0+-11.16.3, …), 1924 product×package rows across 120 product lines (Container suse/sle-micro-rancher/5.2, Container suse/sles/15.2/virt-handler, … (120 product lines)): Fixed 933, Known Not Affected 766, Known Affected 225.	https://www.suse.com/security/cve/CVE-2020-29129/
`ubuntu`	low	CVE-2020-29129 low priority: Ubuntu including 3 source packages (libslirp, qemu, qemu-kvm), 42 status rows across 14 suites (bionic, focal, groovy, hirsute, impish, jammy, kinetic, lunar, mantic, noble, oracular, trusty, upstream, xenial): not-affected 21, DNE 16, released 4, needs-triage 1.	https://ubuntu.com/security/CVE-2020-29129

Affected software / configurations for CVE-2020-29129

Vendor	Product	Version	Raw CPE
libslirp_project	libslirp	<= 4.3.1	cpe:2.3:a:libslirp_project:libslirp::::::::
fedoraproject	fedora	32	cpe:2.3:o:fedoraproject:fedora:32:::::::*
fedoraproject	fedora	33	cpe:2.3:o:fedoraproject:fedora:33:::::::*
debian	debian_linux	10.0	cpe:2.3:o:debian:debian_linux:10.0:::::::*

References for CVE-2020-29129

URL	Tags
http://www.openwall.com/lists/oss-security/2020/11/27/1	Mailing List Third Party Advisory
https://lists.debian.org/debian-lts-announce/2022/09/msg00008.html	Mailing List Third Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/45S5IHSWYITJKMRT23HCHJQDI674AMTQ/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/OPCOHDEONMHH6QPJZKRLLCNRGRYODG7X/
https://lists.freedesktop.org/archives/slirp/2020-November/000115.html	Mailing List Vendor Advisory

URL

CVE-2020-29129

Exploit prediction scoring system (EPSS) score for CVE-2020-29129

Common vulnerability scoring system (CVSS) metrics for CVE-2020-29129

Weakness enumeration for CVE-2020-29129

OS Trackers for CVE-2020-29129

Affected software / configurations for CVE-2020-29129

References for CVE-2020-29129