CVE-2017-16921

CVE-2017-16921 is a high-severity vulnerability in Otrs with a CVSS 3.x base score of 8.8. Its EPSS exploit-prediction score of 20% places it in the 97th percentile, indicating an elevated likelihood of exploitation. The underlying weakness is classified as CWE-78.

Key facts

Description

In OTRS 6.0.x up to and including 6.0.1, OTRS 5.0.x up to and including 5.0.24, and OTRS 4.0.x up to and including 4.0.26, an attacker who is logged into OTRS as an agent can manipulate form parameters (related to PGP) and execute arbitrary shell commands with the permissions of the OTRS or web server user.

Frequently asked questions

What is CVE-2017-16921?
In OTRS 6.0.x up to and including 6.0.1, OTRS 5.0.x up to and including 5.0.24, and OTRS 4.0.x up to and including 4.0.26, an attacker who is logged into OTRS as an agent can manipulate form parameters (related to PGP) and execute arbitrary shell commands with the permissions of the OTRS or web server user.
How severe is CVE-2017-16921?
CVE-2017-16921 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-2017-16921 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 20% (97th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2017-16921?
CVE-2017-16921 primarily affects Otrs. In total, 70 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2017-16921?
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-2017-16921 published?
CVE-2017-16921 was published on 2017-12-08 and last updated on 2026-06-17.

References

Affected products (70)

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