Auth bypass in Mit Krb5-Appl

CVE-2019-25017

An issue was discovered in rcp in MIT krb5-appl through 1.0.3. Due to the rcp implementation being derived from 1983 rcp, the server chooses which files/directories are sent to the client. However, the rcp client only performs cursory validation of the object name returned (only directory traversal attacks are prevented). A malicious rcp server (or Man-in-The-Middle attacker) can overwrite arbitrary files in the rcp client target directory. If recursive operation (-r) is performed, the server can manipulate subdirectories as well (for example, to overwrite the .ssh/authorized_keys file). This issue is similar to CVE-2019-6111 and CVE-2019-7283. NOTE: MIT krb5-appl is not supported upstream but is shipped by a few Linux distributions. The affected code was removed from the supported MIT Kerberos 5 (aka krb5) product many years ago, at version 1.8.

Vulnerability class: Broken Access Control

Published · last modified .

CVSS v3 metric

CVSS v3 base score 5.9 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N.

EPSS exploit prediction

EPSS: 0.014 (70.9th percentile), scored .

Low probability of exploitation in the next 30 days, but still tracked. 71st percentile — 70.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2019-25017: held from 0.014 to 0.014.

EPSS over last 30 days · oldest: 0.014 · newest: 0.014 · change: -0.001

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2019-25017?
CVE-2019-25017 is a medium-severity vulnerability in Mit Krb5-Appl, classified under Incorrect Authorization. CVSS score: 5.9/10. Published 2021-02-02.
How severe is CVE-2019-25017?
Medium severity. CVSS v3 base score is 5.9 out of 10.
Is CVE-2019-25017 known to be exploited?
2 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.