CVE-2020-25669: debian debian_linux Use After Free

Modified

AliasesUBUNTU-CVE-2020-25669DEBIAN-CVE-2020-25669

Published 26-05-2021Last modified 04-08-2024

Vulnerability summary

CVE-2020-25669 is a high (CVSS 7.8) Use After Free vulnerability in debian debian_linux. EPSS estimates a 0.63% chance of exploitation in the next 30 days, higher than 50.1% of scored vulnerabilities. 2 public exploits are recorded.

Priority

Prioritisepublic exploit

Public exploit (reference, Date unknown)

Source freshness unavailable

How is this decided?

CVSS score

7.8/10

010

High · v3.1 (NVD)

EPSS score

0.63%

0%100%

Low · 0.00 pp in 30 days

KEVNot listedNot listed by any tracked catalog.

RansomwareNot flaggedNo ransomware use recorded.

Public exploits2reference

Timeline

26-05-2021
PublishedVulnerability first disclosed.
04-08-2024
Last modifiedVulnerability information updated.

Description

A vulnerability was found in the Linux Kernel where the function sunkbd_reinit having been scheduled by sunkbd_interrupt before sunkbd being freed. Though the dangling pointer is set to NULL in sunkbd_disconnect, there is still an alias in sunkbd_reinit causing Use After Free.

CVSS metrics

4 scores · 3 sources · 2 versions

v3.17.8v2.07.2

EPSS trend

Probability

0.63%

Chance of exploitation in the next 30 days

Percentile

50%

Versus all other CVEs

30-day change

No change 0.00 pp

From 0.63% on 04-10-2026

04-10-202603-11-2026

Known exploited

Compare KEV catalogs

CISA KEV

Not in the CISA KEV catalog.

ENISA CNW

Not in the ENISA CNW catalog.

CIRCL

Not in the CIRCL catalog.

Public exploits

2 found

referenceUnverified
Exploit Reference (openwall.com)
Maturity: unknown
referenceUnverified
Exploit Reference (openwall.com)
Maturity: unknown

Weaknesses

CWE · root cause

CWE-416Use After FreeThe product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.

Affected systems

Version check

Known conditions: local access, low-privilege account, no user interaction (CVSS vector). Other conditions: not stated in public data.

Ubuntu48 products

linuxAll versions (No fix recorded) | < 4.4.0-201.233 | < 4.15.0-136.140 | < 5.4.0-66.74
linux-aws< 4.4.0-1085.89 | < 4.4.0-1121.135 | < 4.15.0-1094.101 | < 5.4.0-1038.40
linux-aws-5.0All versions (No fix recorded)
linux-aws-5.3All versions (No fix recorded)
linux-aws-5.4< 5.4.0-1038.40~18.04.1

linux-aws-fips< 4.15.0-2037.39 | All versions (No fix recorded) | < 5.4.0-1069.73+fips2
linux-aws-hwe< 4.15.0-1094.101~16.04.1
linux-azure< 4.15.0-1108.120~14.04.1 | < 4.15.0-1108.120~16.04.1 | All versions (No fix recorded) | < 5.4.0-1040.42
linux-azure-4.15< 4.15.0-1108.120
linux-azure-5.3All versions (No fix recorded)
linux-azure-5.4< 5.4.0-1040.42~18.04.1
linux-azure-edgeAll versions (No fix recorded)
linux-azure-fde-5.15< 5.15.0-1114.123~20.04.1
linux-azure-fips< 4.15.0-2020.23 | All versions (No fix recorded) | < 5.4.0-1073.76+fips1
linux-dell300x< 4.15.0-1012.16
linux-fips< 4.4.0-1055.61 | All versions (No fix recorded) | < 4.15.0-1053.61
linux-gcp< 4.15.0-1093.106~16.04.1 | All versions (No fix recorded) | < 5.4.0-1037.40
linux-gcp-4.15< 4.15.0-1093.106
linux-gcp-5.3All versions (No fix recorded)
linux-gcp-5.4< 5.4.0-1037.40~18.04.1
linux-gcp-edgeAll versions (No fix recorded)
linux-gcp-fipsAll versions (No fix recorded) | < 5.4.0-1067.71~20.04.1
linux-gke< 5.4.0-1036.38
linux-gke-4.15< 4.15.0-1079.84
linux-gke-5.4< 5.4.0-1036.38~18.04.1
linux-gkeop< 5.4.0-1010.11
linux-gkeop-5.4< 5.4.0-1010.11~18.04.1
linux-hwe< 4.15.0-136.140~16.04.1 | All versions (No fix recorded)
linux-hwe-5.4< 5.4.0-66.74~18.04.2
linux-hwe-5.8< 5.8.0-44.50~20.04.1
linux-hwe-edgeAll versions (No fix recorded)
linux-intel-iot-realtimeAll versions (No fix recorded)
linux-kvm< 4.4.0-1087.96 | < 4.15.0-1085.87 | < 5.4.0-1033.34
linux-lts-xenial< 4.4.0-201.233~14.04.1
linux-oemAll versions (No fix recorded)
linux-oem-5.6< 5.6.0-1053.57
linux-oracle< 4.15.0-1065.73~16.04.1 | < 4.15.0-1065.73 | < 5.4.0-1038.41
linux-oracle-5.0All versions (No fix recorded)
linux-oracle-5.3All versions (No fix recorded)
linux-oracle-5.4< 5.4.0-1038.41~18.04.1
linux-raspi< 5.4.0-1029.32
linux-raspi-5.4< 5.4.0-1029.32~18.04.1
linux-raspi-realtimeAll versions (No fix recorded)
linux-raspi2< 4.4.0-1145.155 | < 4.15.0-1079.84 | All versions (No fix recorded)
linux-realtimeAll versions (No fix recorded)
linux-riscvAll versions (No fix recorded)
linux-riscv-5.8< 5.8.0-17.19~20.04.1
linux-snapdragon< 4.4.0-1149.159 | < 4.15.0-1096.105

Show all 48

Netapp11 products

Show all 11

Debian2 products

linux< 5.9.11-1
debian_linuxEOL9.0

Linux1 product

linux_kernel< 4.4.245 | ≥ 4.5, < 4.9.245 | ≥ 4.10, < 4.14.208 | ≥ 4.15, < 4.19.159 | ≥ 4.20, < 5.4.79 | ≥ 5.5, < 5.9.10

4 vendors · 62 products

References

18 links

www.openwall.com/lists/oss-security/2020/11/05/2Mailing ListX Refsource MLISTExploitThird Party Advisory
www.openwall.com/lists/oss-security/2020/11/20/5Mailing ListX Refsource MLISTExploitThird Party Advisory
lists.debian.org/debian-lts-announce/2020/12/msg00015.htmlMailing ListX Refsource MLISTThird Party Advisory
lists.debian.org/debian-lts-announce/2020/12/msg00027.htmlMailing ListX Refsource MLISTThird Party Advisory
www.openwall.com/lists/oss-security/2020/11/05/2%2CX Refsource MISC
www.openwall.com/lists/oss-security/2020/11/20/5%2CX Refsource MISC
github.com/torvalds/linux/commit/77e70d351db7de07a46ac49b87a6c3c7a60fca7eX Refsource MISCPatchThird Party Advisory
security.netapp.com/advisory/ntap-20210702-0006/X Refsource CONFIRMThird Party Advisory
ubuntu.com/security/CVE-2020-25669REPORT
www.openwall.com/lists/oss-security/2020/11/05/2REPORT

Show all 18 references

ubuntu.com/security/notices/USN-4709-1Advisory
ubuntu.com/security/notices/USN-4708-1Advisory
ubuntu.com/security/notices/USN-4749-1Advisory
ubuntu.com/security/notices/USN-4750-1Advisory
ubuntu.com/security/notices/USN-4751-1Advisory
ubuntu.com/security/notices/USN-4912-1Advisory
www.cve.org/CVERecord?id=CVE-2020-25669REPORT
security-tracker.debian.org/tracker/CVE-2020-25669Advisory