EGI SVG Advisories


Title:   EGI SVG 'ADVISORY' [TLP:WHITE] LOW risk vulnerability in dCache
         macaroon bearer token validation [EGI-SVG-2020-16806]

Date:    2020-08-17

Affected software and risk

LOW risk vulnerability concerning dCache macaroon bearer token validation

Package : dCache

The macaroons are bearer tokens, that can contain a number of restrictions,
The result of IP based verification is not respected when it is combined with
other restrictions.

For more information see [R 1].

Actions required/recommended

Sites are recommended to update relevant components as soon as it is

Sites may update either from the UMD or from the dCache site [R 1]

Component installation information

The official repository for the distribution of grid middleware for EGI sites
is which contains the EGI Unified Middleware Distribution

Sites using the EGI UMD 4 should see:

A fixed version dCache - 5.2.26 is available in the UMD for both SL6 and
CentOS7 in UMD-4.11.2

Sites installing directly from dCache should see [R 1].

More Information

The macaroon based tokens are used by quite a small number of sites and IP
restrictions are used even less.
Few sites are likely to be affected by this vulnerability.

Affected software details

This is fixed in dcache versions  5.2.26, 6.0.20, 6.1.9 and 6.2.1.

Previous supported versions  5.2.x, 6.0.x, 6.1.x and 6.2.x are all affected.

Versions 5.1.x are affected, but these have not been patched as the dCache team
is not aware of any production instances using them.

Versions before 5.1.0 are not affected.


** WHITE information - Unlimited distribution
- see for distribution restrictions **


Minor updates may be made without re-distribution to the sites


Comments or questions should be sent to svg-rat  at

If you find or become aware of another vulnerability which is relevant to EGI
you may report it by e-mail to

report-vulnerability at

the EGI Software Vulnerability Group will take a look according to the
procedure defined in [R 2]

Note that this is undergoing revision to fully handle vulnerabilities in the
EOSC-hub era.


[R 1]

[R 2]


This vulnerability was reported to SVG by Tigran Mkrtchyan from the dCache
team, who have already produced a fix.


Yyyy-mm-dd  [EGI-SVG-2020-16806]

2020-08-04 Vulnerability reported by Tigran Mkrtchyan from the dCache team.
2020-08-04 Acknowledgement from the EGI SVG to the reporter
2020-08-04 Investigation of vulnerability and relevance to EGI carried out by
           (as appropriate)
2020-08-05 EGI SVG Risk Assessment completed
2020-08-05 Assessment by the EGI Software Vulnerability Group reported to the
           software providers
2020-08-07 Updated packages available at the dCache site
2020-08-14 Updated packages updated in the EGI UMD
2020-08-17 Advisory sent to sites


This advisory has been prepared as part of the effort to fulfil EGI SVG's
purpose "To minimize the risk to the EGI infrastructure arising from software

The risk is that assessed by the group, according to the EGI SVG issue handling
procedure [R 2] in the context of how the software is used in the EGI
infrastructure. It is the opinion of the group, we do not guarantee it to be
correct.  The risk may also be higher or lower in other deployments depending
on how the software is used.

This advisory is subject to the Creative commons license and the EGI
Software Vulnerability Group must be credited.

Note that the SVG issue handling procedure is currently under review, to take
account of the increasing inhomogeneity of the EGI infrastructure and the
services in the EOSC-hub catalogue.

On behalf of the EGI SVG,