[critical] Citrix Bleed: NetScaler session token leak (CVE-2023-4966)

Mon, 18 Dec 2023 00:00:00 GMT

A memory leak in NetScaler ADC and Gateway let attackers read session tokens and hijack logged-in sessions, bypassing passwords and MFA. It was exploited as a zero-day from late August 2023, then widely by LockBit affiliates. Victims included Xfinity (35.9M users).

Status: closed · Patch: patched · Fixed in: 14.1-8.50, 13.1-49.15, 13.0-92.19, FIPS/NDcPP builds: see vendor advisory

Latest updates:

2023-12-18: Xfinity discloses that Citrix Bleed exploitation on Oct 16–19 exposed data on 35.9M customers (source)
2023-11-21: CISA, FBI, MS-ISAC and ACSC warn that LockBit 3.0 affiliates are exploiting Citrix Bleed (AA23-325A) (source)
2023-10-23: Citrix issues additional mitigation guidance (source)

CVEs: CVE-2023-4966

[critical] PaperCut MF/NG auth bypass to SYSTEM RCE, used by Cl0p and LockBit (CVE-2023-27350)

Thu, 11 May 2023 00:00:00 GMT

An improper access control bug in PaperCut NG/MF print management let unauthenticated attackers run code as SYSTEM. Fixes had shipped in March 2023, but unpatched servers were exploited from April. Microsoft linked it to Cl0p (Lace Tempest) and LockBit, and the Bl00dy gang hit schools with it.

Status: closed · Patch: patched · Fixed in: 20.1.7, 21.2.11, 22.0.9

Latest updates:

2023-05-11: CISA and FBI advisory AA23-131A: Bl00dy Ransomware Gang targeting education via PaperCut (source)
2023-04-21: PaperCut warns that unpatched servers are being exploited in the wild; CISA adds CVE-2023-27350 to KEV (source)

CVEs: CVE-2023-27350

pwn.watch: LockBit incident updates

[critical] Citrix Bleed: NetScaler session token leak (CVE-2023-4966)

[critical] PaperCut MF/NG auth bypass to SYSTEM RCE, used by Cl0p and LockBit (CVE-2023-27350)