CyberSecBulletin
CVE-2023-27635NVD status: Modified

Debmany: Improper Neutralization of Special Elements in Output Used by a Downstream Component

Published Updated By the CyberSecBulletin desk

CVE-2023-27635 is a high-severity improper neutralization of special elements in output used by a downstream component vulnerability in Debmany from Debian, with a CVSS 3.1 base score of 7.8 out of 10. It can be exploited with local access to the system by an unauthenticated attacker, but only if a user takes part, for example by opening a link or file. Affected Debmany versions: 0.88.1. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.44% chance of exploitation within 30 days, which is low compared with other CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Check which version of Debmany you run against the affected versions below, and install the vendor's latest release.
  2. Read the advisory on bugs.debian.org for workarounds and exact fixed builds.
  3. Because the attack needs a user to take part, warn users about unexpected links and files related to this product until it is patched.

Affected products and versions

VendorProductAffected versionsFixed in
DebianDebmany0.88.1Not stated

Version data comes from NVD's product matching. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
LocalThe attacker needs local access or must trick a user into running something.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
NoneNo account or login is needed.
User interaction
RequiredA user must take an action such as opening a file or link.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
HighAll data handled by the component can be read.
Integrity
HighData or code can be modified at will.
Availability
HighThe component can be taken down completely.

Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H. Scored by NVD.

Official description

debmany in debian-goodies 0.88.1 allows attackers to execute arbitrary shell commands (because of an eval call) via a crafted .deb file. (The path is shown to the user before execution.)

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Improper Neutralization of Special Elements in Output Used by a Downstream Component

The product constructs all or part of a command, data structure, or record using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify how it is parsed or interpreted when it is sent to a downstream component.

How developers prevent this class of flaw

  • Programming languages and supporting technologies might be chosen which are not subject to these issues.
  • Utilize an appropriate mix of allowlist and denylist parsing to filter control-plane syntax from all input.

More Improper Neutralization of Special Elements in Output Used by a Downstream Component vulnerabilities (CWE-74)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
  3. Record last changed materially (score, affected products, status or references).

References

Recent Improper Neutralization of Special Elements in Output Used by a Downstream Component vulnerabilities

Spotted an error? Tell us.