CVE-2021-33393

CVE-2021-33393 is a high-severity vulnerability in Ipfire with a CVSS 3.x base score of 8.8. Its EPSS exploit-prediction score of 59% places it in the 99th percentile, indicating an elevated likelihood of exploitation.

Key facts

Description

lfs/backup in IPFire 2.25-core155 does not ensure that /var/ipfire/backup/bin/backup.pl is owned by the root account. It might be owned by an unprivileged account, which could potentially be used to install a Trojan horse backup.pl script that is later executed by root. Similar problems with the ownership/permissions of other files may be present as well.

Frequently asked questions

What is CVE-2021-33393?
lfs/backup in IPFire 2.25-core155 does not ensure that /var/ipfire/backup/bin/backup.pl is owned by the root account. It might be owned by an unprivileged account, which could potentially be used to install a Trojan horse backup.pl script that is later executed by root. Similar problems with the ownership/permissions of other files may be present as well.
How severe is CVE-2021-33393?
CVE-2021-33393 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2021-33393 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 59% (99th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-33393?
CVE-2021-33393 primarily affects Ipfire. In total, 15 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-33393?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2021-33393 published?
CVE-2021-33393 was published on 2021-06-09 and last updated on 2026-06-17.

References

Affected products (15)

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